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Why Fusion Is More Powerful Than Fission | Neil deGrasse Tyson Explains...

Video vocabulary

conventional

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US / kən'venʃənl /

UK / kənˈvɛnʃənəl /

B2
  • adjecitve
  • Following the common attitudes and practices

film

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US / fɪlm /

UK / fɪlm /

A2
  • noun
  • Thin layer that covers something
  • Movie
  • verb
  • To record moving action with a camera

next

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US / nekst /

UK / nɛkst /

A1
  • adverb
  • The one that follows another in time or order
  • At a time or place directly after the present one
  • noun
  • The one that follows after
  • adjecitve
  • Immediately after the previous one
  • First occurrence after the present one

mind

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US / maɪnd /

UK / maɪnd /

A1
  • noun
  • One's opinion or way of thinking about something
  • Part of humans that allows us to think or feel
  • verb
  • To be bothered or upset by something
  • To take care of someone e.g. as a bodyguard

problem

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US / ˈprɒbləm /

UK / ˈprɑbləm /

A1
  • adjecitve
  • Causing trouble
  • noun
  • Something difficult to deal with or causes trouble
  • Question to show understanding of a math concept

scientist

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US / ˈsaɪəntɪst /

UK / ˈsaɪəntɪst /

A2
  • noun
  • Person who is trained in a science

century

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US / 'sentʃərɪ /

UK / ˈsɛntʃəri /

A1
  • noun
  • Period of 100 years

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

tyson

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US / ˈtaɪsən /

UK / /

A1

part

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US / pɑ:t /

UK / pɑ:rt /

A1
  • adjecitve
  • To some degree; half; not fully
  • noun
  • Division of a book
  • Ratio of something, e.g. 3 of gin, 1 of tonic
  • A line in a person's hair, made with a comb
  • Character an actor plays on stage, movie, or TV
  • Some, but not all of a specific thing
  • Role in causing something to happen
  • verb
  • To make a line in a person's hair, by using a comb
  • To move two things apart creating a space
  • To leave someone, or to break off a relationship

tonight

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US / təˈnaɪt /

UK / təˈnaɪt /

A1
  • adverb
  • Night following this day
  • noun
  • This evening; the night of today

annihilate

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US / ə'naɪəleɪt /

UK / əˈnaɪəˌlet /

C1
  • verb
  • To completely destroy, or get rid of, by force

blood

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US / blʌd /

UK / blʌd /

A2
  • adjecitve
  • Related by birth; family
  • noun
  • Red liquid in the bodies of people and animals
  • verb
  • To be initiated into something, e.g. a secret club

calculate

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US / 'kælkjʊleɪt /

UK / ˈkælkjəˌlet /

B2
  • verb
  • To find an answer using mathematics
  • To make an educated guess about something

handiwork

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US / ˈhændiwɜ:k /

UK / ˈhændiˌwə:k /

C1
  • noun
  • Making something by hand labor or your own efforts

hundred

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US / 'hʌndrəd /

UK / ˈhʌndrɪd /

A1
  • number
  • 100

rapidly

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US / 'ræpɪdlɪ /

UK / ˈræpɪdlɪ /

B1
  • adverb
  • With great speed; quickly

world

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US / wɜ:ld /

UK / wɜrld /

A1
  • noun
  • All the humans, events, activities on the earth
  • Political division due to some kind of similarity

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

know

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US / nəʊ /

UK / noʊ /

A1
  • verb
  • To be familiar with a person or place, thing
  • To feel sure or be convinced about something
  • To discover or be aware of something
  • To be able to distinguish
  • To have knowledge of things

slightly

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US / ˈslaɪtli /

UK / ˈslaɪtli /

B1
  • adverb
  • Only a little

honest

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US / ˈɒnɪst /

UK / ˈɑnɪst /

A2
  • adjecitve
  • Good, truthful, sincere, or faithful; trustworthy

store

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US / stɔ:(r) /

UK / stɔr, stor /

A2
  • noun
  • Place where things are kept for future use
  • Place where you can go to buy things
  • verb
  • To put things in a place for later use

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together

air

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US / eə(r) /

UK / er /

A1
  • noun
  • Mixture of gases around the earth that we breathe
  • A person's manner intended to impress others
  • verb
  • To expose to the outside, to dry or freshen
  • To broadcast a TV or radio show
  • To open a subject to discussion and debate

break

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US / breɪk /

UK / brek /

A1
  • noun
  • Time you stop an activity before continuing
  • End of a relationship
  • An escape from a place such as a jail
  • (Lucky) advantage or benefit from something
  • Find a solution or answer to a problem or crime
  • Change in the weather
  • verb
  • To create a new record e.g. running the 100m dash
  • To form a crack in something
  • To burst or become damaged
  • To end a relationship
  • To escape from a place such as a jail
  • To train a wild animal e.g. a horse
  • To separate into pieces by force, or by dropping
  • To act against a law, rule, or promise
  • To become known suddenly, as in the news
  • To not do what you promised e.g. not keep promises
  • To solve a crime, or answer a problem
  • To stop functioning properly
  • To suddenly start, open or commence
  • To change in pitch suddenly, as in a voice
  • To fall on the shore, as in waves
  • To begin or change suddenly; the dawn or weather
  • To defeat by causing the person to lose their will

hear

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US / hɪə(r) /

UK / hɪr /

A1
  • verb
  • To be aware of sound; to perceive with the ear
  • To be told or find out information or facts
  • To consider or listen to a court case

occasion

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US / ə'keɪʒn /

UK / əˈkeʒən /

A2
  • noun
  • Significant or important event or function
  • Time when something happens or takes place
  • verb
  • To make or cause something to happen; to lead to

full

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US / fʊl /

UK / fʊl /

A1
  • adjecitve
  • Containing all the parts; complete
  • Containing or holding as much as possible
  • Having had enough food
  • adverb
  • In a direct manner; completely

pure

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US / pjʊə(r) /

UK / pjʊr /

A2
  • adjecitve
  • Not mixed with anything else
  • Being morally good

sun

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US / sʌn /

UK / sʌn /

A1
  • noun
  • Light and heat coming from a large star in the sky
  • Hot shining star the Earth moves around
  • verb
  • To lie in the sunshine and enjoy its warmth

end

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US / end /

UK / ɛnd /

A1
  • noun
  • The point where a process or activity stops
  • A point that marks the limit of something; finish
  • Goal or desired result
  • The tip, edge or limit of something
  • verb
  • To be the last part of something

engineer

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US / ˌendʒɪ'nɪə(r) /

UK / ˌɛndʒəˈnɪr /

A2
  • noun
  • Someone whose job is designing machines, buildings
  • Someone whose job is to repair or maintain engines

count

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US / kaʊnt /

UK / kaʊnt /

A2
  • noun
  • Number of things added together, e.g. votes
  • With the number of crimes, knockouts, as stated
  • verb
  • To add things together to find the total number
  • To matter or be important
  • To include someone or something in a final number

extraordinary

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US / ɪkˈstrɔ:dnri /

UK / ɪkˈstrɔ:rdəneri /

B1
  • adjecitve
  • Beyond what is ordinary; very unusual; remarkable

fall

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US / fɔ:l /

UK / fɔl /

A1
  • noun
  • Season after summer and before winter; Autumn
  • A drop in amount; decrease
  • Dropping from a standing position to the ground
  • verb
  • To drop in amount; to decrease
  • To come down from a higher position suddenly
  • To go from standing to the ground, by accident

accord

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US / ə'kɔ:d /

UK / əˈkɔ:rd /

B1
  • noun
  • Agreement or harmony
  • An agreement or treaty between countries
  • verb
  • To be in harmony or agreement; consent
  • To give (someone) the respect due to them

freeway

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US / 'fri:weɪ /

UK / ˈfriˌwe /

C1
  • noun
  • Highway that can be used without paying a toll

lithium

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US / ˈlɪθiəm /

UK / ˈlɪθiəm /

A1
  • noun
  • Soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in s

low

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US / ləʊ /

UK / lo /

A1
  • adjecitve
  • Having a small quantity, supply, or amount
  • Being unhappy or unpleasant in attitude
  • Not high; being near the ground, or bottom
  • (Of a voice, sound) being soft; quiet
  • noun
  • Situation of not having a lot of something

see

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US / si: /

UK / si /

A1
  • verb
  • To go on a date with someone
  • To predict whether something is, or will be true
  • To understand what someone says
  • To use your eyes to look at something
  • To visit a place often for sightseeing or pleasure
  • To visit or meet with someone
  • To find out by waiting or looking
  • To watch (a game, movie or TV show)

encounter

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US / ɪn'kaʊntə(r) /

UK / ɛnˈkaʊntɚ /

B1
  • noun
  • A chance meeting; unexpected or unplanned meeting
  • verb
  • To come up against a problem or trouble; meet
  • To meet someone or something unexpectedly

heal

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US / hi:l /

UK / hi:l /

B1
  • verb
  • To recover from or forget a bad experience
  • To make or become healthy or well again

less

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US / les /

UK / lɛs /

A1
  • adjecitve
  • Smaller in amount or degree
  • adverb
  • To a smaller degree
  • noun
  • A smaller amount
  • preposition
  • With the subtraction of

free

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US / fri: /

UK / fri /

A1
  • adjecitve
  • Living, happening without being controlled
  • Costing no money
  • Not working; not busy
  • verb
  • To release (e.g. bird) from a cage or prison

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

tremendous

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US / trəˈmendəs /

UK / trɪˈmɛndəs /

B1
  • adjecitve
  • Very good or very impressive

able

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US / 'eɪbl /

UK / ˈebəl /

A2
  • adjecitve
  • Skilled; good at something
  • Having the ability to do something

three

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US / θri: /

UK / θri /

A1
  • number
  • Number 3

welcome

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US / 'welkəm /

UK / ˈwɛlkəm /

A1
  • adjecitve
  • Being what was wanted or needed
  • noun
  • Friendly greeting to someone who has arrived
  • verb
  • To greet someone who has just arrived
  • To accept or receive something happily and gladly

explainer

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US / ɪksp'leɪnə /

UK / ɪksp'leɪnə /

A1
  • noun
  • Someone giving reasons or details about something

into

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US / 'ɪntə /

UK / ˈɪntu /

A1
  • preposition
  • Moving or going inside something
  • In the same direction as; in the direction of
  • So as to become; taking the state of

instantaneously

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US / ˌɪnstən'teɪnɪəslɪ /

UK / ˌɪnstənˈtenɪəslɪ /

B1
  • adverb
  • Without any delay at all

perfect

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US / 'pɜ:fɪkt /

UK / ˈpɚfɪkt /

A1
  • adjecitve
  • So good it cannot be improved
  • verb
  • To do something so well, it cannot be done better

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

power

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US / 'paʊə(r) /

UK / ˈpaʊɚ /

A1
  • noun
  • Legal or official right to perform certain actions
  • Ability to move forcefully and quickly
  • Energy of something (e.g. electricity or fuel)
  • Mathematical way to multiply a number
  • Condition of being in political control
  • Physical force, energy, and strength
  • verb
  • To give energy to something, e.g. by electricity
  • To move something forcefully and quickly

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

than

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US / ðən /

UK / ðən /

A1
  • conjunction
  • Used to compare two things that are not equal

turn

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US / tɜ:n /

UK / tɚn /

A1
  • noun
  • Place where changing of direction happens
  • Your time or chance to perform a duty
  • Your chance to play or do in say a game
  • Unexpected change, as in the weather
  • verb
  • To become (a particular age)
  • To become a different quality, color, etc.
  • To change the direction of something, e.g. a car
  • To move in an opposite direction or position
  • To shape metal with a spinning tool

statistic

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US / stəˈtɪstɪk /

UK / stəˈtɪstɪk /

B1
  • noun
  • Number that represents a piece of information

also

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US / 'ɔ:lsəʊ /

UK / ˈɔlso /

A1
  • adverb
  • In addition; too; in a similar way

climate

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US / ˈklaɪmət /

UK / ˈklaɪmɪt /

A2
  • noun
  • Typical weather conditions in a particular place

how

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US / haʊ /

UK / haʊ /

A1
  • adjecitve
  • To what degree? in what amount?
  • adverb
  • (Used to explain the way to do something)
  • exclamation
  • For what purpose or reason?
  • (Used to ask someone or something's condition)

thermonuclear

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US / ˌθɜ:məʊˈnju:kliə(r) /

UK / ˌθɜ:rmoʊˈnu:kliə(r) /

C1
  • adjecitve
  • Using nuclear weapons based on fusion

centrifuge

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US / ˈsentrɪfju:dʒ /

UK / ˈsɛntrəˌfjudʒ /

A1
  • noun
  • Machine to separate substances in a laboratory

lead

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US / li:d /

UK / lid /

A1
  • adjecitve
  • Being the main part in movies or plays
  • noun
  • Wire for electricity, computer, etc.; cable
  • Information that could help to solve a crime
  • Main part in a play or movie
  • Heavy, gray metal element
  • Rope used to tie something to stop it escaping
  • Act of being at the front in a race or game
  • verb
  • To show the way or guide others
  • To be at the front of a race or game
  • To travel in front of; go in advance of others

let

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US / let /

UK / lɛt /

A1
  • verb
  • To allow someone to do something
  • Introducing a suggestion to do something together
  • To rent a house, etc. to others

material

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US / məˈtɪəriəl /

UK / məˈtɪriəl /

A2
  • adjecitve
  • Relevant; (of evidence) important or significant
  • Belonging to the world of physical things
  • noun
  • Cloth; fabric
  • Supplies or data needed to do a certain thing
  • Substance from which a thing is made of

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

wow

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US / waʊ /

UK / waʊ /

A1
  • exclamation
  • Sound people make when they make are impressed
  • verb
  • (Informal) to greatly impress someone

vary

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US / ˈveəri /

UK / ˈveri /

A2
  • verb
  • To change something and make it different
  • To be changeable, both up and down

budget

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US / 'bʌdʒɪt /

UK / ˈbʌdʒɪt /

A2
  • adjecitve
  • Low cost; inexpensive
  • noun
  • Amount of money planned to be spent
  • verb
  • To make a plan for how to spend your money

forest

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US / 'fɒrɪst /

UK / ˈfɔrɪst, ˈfɑr- /

A1
  • noun
  • Large area with many trees

phenomenon

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US / fə'nɒmɪnən /

UK / fɪˈnɑməˌnɑn, -nən /

B1
  • noun
  • Unusual event, fact that can be studied
  • Interesting or unusual person, group
  • something that exists and can be seen, felt, tasted, etc., especially something unusual or interesti

make

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US / meɪk /

UK / mek /

A1
  • noun
  • Product made by a particular company; brand
  • verb
  • To arrange or prepare something e.g. dinner
  • To get to (a place) on time
  • To gain the status of (teacher, lawyer, etc.)
  • To create something by putting things together
  • To earn a certain amount of money at a job
  • To cause or force a person to do something
  • To cause something to happen or be formed

order

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US / 'ɔ:də(r) /

UK / ˈɔrdɚ /

A1
  • noun
  • Religious or social group, as of nuns
  • Instructions to others to do what you want
  • State in which things are neat and organized
  • What you ask to buy, e.g. food in restaurant
  • Social or political control of an area
  • verb
  • To put things in a sequence, e.g. a, b, c
  • To give instructions to others to do what you want
  • To ask for something you want to buy, e.g. a meal

statistical

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US / stə'tɪstɪkl /

UK / stəˈtɪstɪkəl /

B1
  • adjecitve
  • Concerning the math of data

universe

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US / ˈju:nɪvɜ:s /

UK / ˈjunəˌvɚs /

B2
  • noun
  • All of space that contains planets and stars
  • Things surrounding a person, affecting their life

apparently

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US / əˈpærəntli /

UK / əˈpærəntlɪ /

A2
  • adverb
  • According to what you heard; from what can be seen

level

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US / 'levl /

UK / ˈlɛvəl /

A2
  • adjecitve
  • (Sports) equal to another
  • Being steady and determined (e.g. a voice)
  • noun
  • Specific height of something
  • Amount of ability you have compared to others
  • Floor or deck within a building
  • Tool used to determine if something is lying flat
  • verb
  • To aim a gun at someone
  • To destroy a building; flatten an area completely
  • To make things flat or even
  • To make a score equal to another, in sports

nazi

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US / ˈnɑ:tsi /

UK / ˈnɑtsi, ˈnæt- /

A1
  • noun
  • Relating to or consistent with or typical of the ideology and practice of Nazism or the Nazis

neutron

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US / ˈnu:ˌtrɔn, ˈnju:- /

UK / ˈnuˌtrɑn, ˈnju- /

A1
  • noun
  • Charge and mass about equal to a proton; enters into the structure of the atomic nucleus

man

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US / mæn /

UK / mæn /

A1
  • noun
  • Humans in general, including male and female
  • An adult male human being
  • Male who acts in a masculine way; not like a woman
  • verb
  • To control or operate (a machine); be in charge of
  • To operate a machine (a boat, etc.)

runaway

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US / ˈrʌnəweɪ /

UK / ˈrʌnəˌwe /

C2
  • adjecitve
  • (Of a victory) easy; hardly contested
  • Unhappy child who runs away from home
  • noun
  • Unhappy child who runs away from home

fuse

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US / fju:z /

UK / fjuz /

B2
  • noun
  • Device connected to and making a bomb explode
  • Electrical safety device
  • verb
  • (Metal) to become one through heat contact

whose

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US / hu:z /

UK / huz /

A1
  • pronoun
  • Refers to the person who owns something

again

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US / ə'ɡen /

UK / əˈɡɛn /

A1
  • adverb
  • One more time, once more

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

different

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US / ˈdɪfrənt /

UK / ˈdɪfrənt /

A1
  • adjecitve
  • Not of the same kind; unlike other things

care

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US / keə(r) /

UK / kɛr /

A1
  • noun
  • Treatment you receive for your health or safety
  • Something that a person worries about
  • verb
  • To feel interest, concern, or worry
  • To look after someone or something

even

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US / 'i:vn /

UK / ˈivən /

A1
  • adjecitve
  • Being equal in influence, power, possibility etc.
  • Being divided equally or fairly
  • (Of teams/contest) with similar chances of success
  • Smooth, level, or regular
  • Can be divided by 2; ending in 2, 4, 6, 8, or 0
  • At a regular, equally steady manner
  • Remaining steady and unchanging
  • adverb
  • (When this is surprising) as well; too
  • (Used to compare two things/stress the difference)
  • verb
  • To make something level; to flatten
  • To make something equal

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

people

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US / 'pi:pl /

UK / ˈpipəl /

A1
  • noun
  • Persons sharing culture, country, background, etc.
  • Men, Women, Children

reaction

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US / rɪ'ækʃn /

UK / riˈækʃən /

A2
  • noun
  • Bodily response to a drug or something eaten
  • Feeling or action in response to something

sit

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US / sɪt /

UK / sɪt /

A1
  • verb
  • To take an exam
  • To be in a resting position on a chair
  • To provide seating for people
  • To remain in a still position while being painted

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

access

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US / 'ækses /

UK / ˈæksɛs /

A2
  • noun
  • Way to enter a place, e.g. a station or stadium
  • verb
  • To be able to use or have permission to use

down

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US / daʊn /

UK / daʊn /

A1
  • adjecitve
  • Being sad, sick, or unhappy
  • Not operating, working, or functioning as expected
  • adverb
  • In a sitting or lying position
  • Towards or on the ground, floor, or bottom
  • Written or copied onto a piece of paper or book
  • noun
  • A period of play in American Football
  • The soft, smooth hairs that cover a bird's body
  • preposition
  • Along something's path, course, or direction
  • Going from a higher position to a lower position
  • verb
  • To eat or drink very quickly and without stopping

fire

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US / 'faɪə(r) /

UK / faɪr /

A1
  • noun
  • Heat and the flame produced when burning
  • Intense energy for or about something
  • verb
  • To apply heat to something to make it hard
  • To make a person leave their job; dismiss
  • To shoot a gun or weapon
  • To launch something into the sky, e.g. a rocket
  • To start working on something e.g. a project

force

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US / fɔ:s /

UK / fɔrs, fors /

A1
  • noun
  • Group of persons trained for military action; army
  • Pressure; attraction
  • The use of physical strength/violence to persuade
  • verb
  • To use physical strength or violence to persuade

physic

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US / 'fɪzɪk /

UK / 'fɪzɪk /

A1
  • noun
  • (Archaic) medicine causing evacuation of the bowels

physicist

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US / ˈfɪzɪsɪst /

UK / ˈfɪzɪsɪst /

B2
  • noun
  • Person who studies and works in physics

must

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US / məst /

UK / mʌst /

A1
  • noun
  • Something that is necessary or required
  • other
  • (Used to state that something ought to be true)
  • Used to say something is required or necessary

purify

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US / ˈpjʊərɪfaɪ /

UK / ˈpjʊrɪfaɪ /

B2
  • verb
  • To make pure by removing unwanted substances
  • To make someone feel pure by removing guilt

slowly

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US / ˈsləʊli /

UK / ˈsloʊli /

A1
  • adverb
  • In an unhurried or not speedy manner

then

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US / ðen /

UK / ðɛn /

A1
  • adverb
  • A time that is not now
  • Following another thing in time or arrangement
  • Following on reasonably from what was just stated
  • At that time, not now

uranium

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US / juˈreɪniəm /

UK / jʊˈreniəm /

A1
  • noun
  • Radioactive element used for nuclear energy/weapon

vaporize

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US / 'veɪpəraɪz /

UK / ˈvepəˌraɪz /

A1
  • verb
  • To kill to make something completely disappear

energy

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US / 'enədʒɪ /

UK / ˈɛnədʒi /

A2
  • noun
  • Physical or mental strength

enough

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US / ɪˈnʌf /

UK / ɪˈnʌf /

A1
  • adjecitve
  • Sufficient to answer the need
  • adverb
  • To a satisfactory degree
  • pronoun
  • Equal to what is needed; as much as required
  • Adequate number or amount

jong

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US / dʒɔŋ /

UK / /

A1
  • exclamation
  • Used to express surprise, pleasure, or anger, or to add emphasis to a statement.
  • noun
  • A young black male servant.
  • Used as a form of address to both men and women, expressing affection or exasperation.

wield

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US / wi:ld /

UK / wild /

B2
  • verb
  • To exercise (authority or influence, for example)

baby

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US / ˈbeɪbi /

UK / ˈbeɪbi /

A2
  • adjecitve
  • Small in size; smaller than usual
  • noun
  • A very young child, who cannot yet speak
  • verb
  • To treat someone as if they were newly born

disappear

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US / ˌdɪsəˈpɪə(r) /

UK / ˌdɪsəˈpɪr /

A1
  • verb
  • To no longer see because it's not there any more

right

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US / raɪt /

UK / raɪt /

A1
  • adjecitve
  • Correct or true
  • The south side of you looking at the rising sun
  • adverb
  • Exactly in a place or time
  • Being appropriate for a particular event
  • In a straight or direct manner
  • noun
  • Something you are legally or morally allowed to do
  • Ideal of what is just and good
  • Political view based on conservatism
  • verb
  • To fix something previously wrong or unjust
  • To make upright, as a boat that has turned over

hydrogen

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US / ˈhaɪdrədʒən /

UK / ˈhaɪdrədʒən /

B1
  • noun
  • Lightest of all chemical elements

sequence

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US / 'si:kwəns /

UK / ˈsikwəns, -ˌkwɛns /

A2
  • noun
  • Part of a movie showing one part of the story
  • verb
  • To arrange things in an order they should happen

own

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US / əʊn /

UK / on /

A1
  • adjecitve
  • Belong to oneself
  • determiner
  • Yours, his, hers, etc.; not belonging to another
  • pronoun
  • (Something) belong to myself
  • verb
  • To have something as your property

element

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US / 'elɪmənt /

UK / ˈɛləmənt /

A2
  • noun
  • Essential or particular part of something

get

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US / ɡet /

UK / ɡɛt /

A1
  • verb
  • To become affected by illness or disease
  • To begin to feel or understand an emotion or idea
  • To send or bring someone or something home, etc.
  • To go somewhere to obtain something
  • To (cause to) do a particular thing
  • To obtain, receive or be given something
  • To currently have
  • To prepare for use
  • To understand something being said or read

first

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US / fɜ:st /

UK / fɚst /

A1
  • adjecitve
  • 1st; Coming before all others in time or place
  • noun
  • Something that has not happened before
  • Position of the winner of a competition

radioactivity

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US / ˌreɪdɪəʊæk'tɪvətɪ /

UK / ˌredioækˈtɪvɪti /

B2
  • noun
  • Emission of electromagnetic rays in nuclear decay

unbelievable

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US / ˌʌnbɪˈli:vəbl /

UK / ˌʌnbɪˈlivəbəl /

B1
  • adjecitve
  • Being very hard to believe; very great

bottom

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US / 'bɒtəm /

UK / ˈbɑtəm /

A2
  • adjecitve
  • Concerning the part under something, e.g. a vase
  • noun
  • The part of your body you sit on
  • Lowest position, often in a company or contest
  • Lowest part of something; part on which it rests
  • Lowest level, part or point of an object
  • The part under something, e.g. a vase
  • verb
  • To hit the lowest part of something

bow

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US / baʊ /

UK / bo /

A2
  • noun
  • Wooden weapon made to shoot arrows
  • Front part of a boat
  • Knot with two loops used to tie shoelaces, etc.
  • Wood tool with horse hair used to play a violin
  • verb
  • To (cause to) curve or bend
  • To bend forward at waist in order to show respect

city

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US / 'sɪtɪ /

UK / ˈsɪti /

A1
  • noun
  • Area with many buildings, roads and people

bomb

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US / bɒm /

UK / bɑm /

B1
  • noun
  • An explosive device
  • verb
  • To attack with explosives
  • To fail or be completely unsuccessful

example

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US / ɪgˈzɑ:mpl /

UK / ɪɡˈzæmpəl /

A1
  • noun
  • Thing, person which represents a category

happen

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US / 'hæpən /

UK / ˈhæpən /

A1
  • verb
  • To take place or occur

yeah

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US / jeə /

UK / ˈjɛə, ˈjæə, jɛ- /

A1
  • exclamation
  • Another way of saying 'yes'

catch

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US / kætʃ /

UK / kætʃ, kɛtʃ /

A1
  • noun
  • Amount of something that has been caught
  • Trick or something trying to deceive
  • verb
  • To stop something flying and hold it
  • To stop something and not let it go, e.g. animals
  • To get sick or get a disease from someone else
  • To find someone to do something, a task
  • To get stuck on or in something
  • To be trapped so you can’t escape
  • To be able to understand what someone is saying

disrupt

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US / dɪsˈrʌpt /

UK / dɪsˈrʌpt /

B2
  • verb
  • To cause a disturbance in an activity in progress

interesting

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US / ˈɪntrəstɪŋ /

UK / ˈɪntrɪstɪŋ, -tərɪstɪŋ, -təˌrɛstɪŋ /

A1
  • adjecitve
  • Taking your attention; making you want to know
  • verb
  • To make someone want to know about something
  • To persuade to do, become involved with something

hit

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US / hɪt /

UK / hɪt /

A1
  • noun
  • A planned killing, usually for money
  • Song, movie etc. that is successful
  • When someone strikes someone or something
  • Time when a player makes contact with the ball
  • Time when a website is accessed
  • verb
  • To have a negative impact on a person/place/thing
  • To press something, such as a button or switch
  • To suddenly realize the importance of something
  • To move your hand, a bat, etc. against with force
  • To fight, attack or damage something or someone
  • To arrive at a specific place, level, or goal
  • To make contact with the ball in a game or sport

number

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US / ˈnʌmbə(r) /

UK / ˈnʌmbɚ /

A1
  • noun
  • Symbols such as 1, 2, 56, 793
  • Particular song or dance performed during a show
  • Total quantity or amount of things
  • verb
  • To put numbers on things
  • To assign a sequence within a group, series, set
  • To claim to be part of a larger group, series, set

soot

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US / sʊt /

UK / sʊt, sut /

C1
  • noun
  • Fine, black powder produced during burning

square

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US / skweə(r) /

UK / skwɛr /

A2
  • adjecitve
  • Being fair or honest
  • Multiply a number by itself e.g. 2x2 or 6x6
  • noun
  • Shape with 4 equal length sides and 4 equal angles
  • The result of multiplying Length by the width
  • Open public area in the middle of the town
  • verb
  • To make something balance or be equal
  • To multiply a number by itself, e.g. 2x2 or 6x8
  • To straighten the edge to form a four-sided shape

tell

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US / tel /

UK / tɛl /

A1
  • verb
  • To (strongly) advise a person to do something
  • To be able to guess
  • To say or communicate information to someone
  • To inform, but without speaking; indicate
  • To have a negative effect on someone
  • To order someone to do something; command
  • To recognize something based on certain signs
  • To report something to an authority
  • To explain something or teach someone something

continue

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US / kən'tɪnju: /

UK / kənˈtɪnju /

A1
  • verb
  • To do something without stopping, or after pausing
  • To start doing again after a break, pause, or stop

ignorant

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US / ˈɪgnərənt /

UK / ˈɪɡnərənt /

B1
  • adjecitve
  • Lacking knowledge, awareness or information

massive

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US / ˈmæsɪv /

UK / ˈmæsɪv /

B1
  • adjecitve
  • Very big; large; too big

science

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US / 'saɪəns /

UK / ˈsaɪəns /

A2
  • noun
  • Study of the physical world, based on facts

sort

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US / sɔ:t /

UK / sɔrt /

A1
  • noun
  • Group or class of similar things or people
  • verb
  • To organize things by putting them into groups
  • To deal with things in an organized way

should

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US / ʃʊd /

UK / ʃʊd /

A1
  • other
  • Used to indicate what is proper or reasonable

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

new

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US / nju: /

UK / nu, nju /

A1
  • adjecitve
  • Not old, recently born, built or made
  • Being or doing something for the first time
  • Not felt, seen or known previously
  • Having been recently bought or obtained

lose

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US / lu:z /

UK / luz /

A1
  • verb
  • To be unable to keep in check or control something
  • To decrease in value or quantity (e.g. weight)
  • To stop having certain qualities or abilities
  • To stop having or being entitled to
  • To fail to win something that is being contested
  • To be unable to find something you once had
  • To be dependent on someone (used with 'not')

small

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US / smɔ:l /

UK / smɔl /

A1
  • adjecitve
  • Little in size; not big
  • (Of letters) not written in capital letters
  • Being insignificant or minor
  • (Of a business) with few people or things; local
  • (Of voice) being soft and quiet
  • (Of a child) being young

actually

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US / ˈæktʃuəli /

UK / ˈæktʃuəli /

A1
  • adverb
  • Used to add new (often different) information

antimatter

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US / ˈæntimætə(r) /

UK / ˈæntɪˌmætɚ, ˈæntaɪ- /

C2
  • noun
  • Matter consisting of elementary antiparticles

catapult

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US / 'kætəpʌlt /

UK / ˈkætəˌpʌlt,-ˌpʊlt /

B2
  • noun
  • Weapon that projects rocks from an elastic strap

deserve

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US / dɪ'zɜ:v /

UK / dɪˈzɚv /

A2
  • verb
  • To be worthy of, e.g. getting praise or attention

comfort

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US / 'kʌmfət /

UK / ˈkʌmfət /

A2
  • noun
  • Acts or words that reduce pain or sadness
  • State of being relaxed, warm or happy
  • verb
  • To try to make distressed person feel better

radioactive

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US / ˌreɪdɪəʊ'æktɪv /

UK / ˌredioˈæktɪv /

B2
  • adjecitve
  • Emitting harmful energy from nuclear activity

realize

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US / 'ri:əlaɪz /

UK / ˈriəˌlaɪz /

A1
  • verb
  • To become aware of or understand mentally

use

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US / ju:s /

UK / ju:s /

A1
  • noun
  • Ability to employ something
  • Need to enable it to work
  • Permission to do something with something
  • Act of spending money
  • Operation of a machine for its function
  • verb
  • To have; to eat, drink, consume etc.
  • To need to operate or work
  • To operate a machine, e.g. a computer
  • To treat a person badly
  • To do something with, for a task or purpose

cram

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US / kræm /

UK / kræm /

B2
  • verb
  • To add more to something that is already full
  • To study intensively (for a test)

maverick

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US / 'mævərɪk /

UK / ˈmævərɪk, ˈmævrɪk /

C1
  • noun
  • Person who does not like to follow the rules

particle

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US / ˈpɑ:tɪkl /

UK / ˈpɑrtɪkəl /

B1
  • noun
  • Adverb or preposition that joins with a verb
  • Tiny piece or quantity of something

pulse

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US / pʌls /

UK / pʌls /

B1
  • noun
  • Regular beating of a heart
  • verb
  • To beat in a rhythm

true

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US / tru: /

UK / tru: /

A1
  • adjecitve
  • Agreeing with the facts; not false; real or actual

story

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US / 'stɔ:rɪ /

UK / ˈstɔri, ˈstori /

A1
  • noun
  • One of many floors or levels in a building
  • Account or description of how something happened

weird

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US / wɪəd /

UK / wɪrd /

B1
  • adjecitve
  • Odd or unusual; surprising; strange

combine

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US / kəmˈbaɪn /

UK / kəmˈbaɪn /

A2
  • verb
  • To mix several things together to form one thing

certain

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US / ˈsə:tn /

UK / ˈsɚtn /

A1
  • adjecitve
  • Definite, fixed
  • Referring to an unspecified amount or quantity
  • Being sure about something; without doubt

point

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US / pɔɪnt /

UK / pɔɪnt /

A1
  • noun
  • An item to be discussed
  • Small spot or dot
  • Fact or detail
  • Feature of something
  • The size of the text on a page or screen
  • A certain time or stage in a process
  • Certain position in time or space
  • Idea or fact you try to convince people about
  • Measurement of scores in a game, sport
  • Sharp end of something, e.g. a pen or pin
  • verb
  • To face a certain direction, e.g. north
  • To indicate something with your finger to others

sure

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US / ʃʊə(r) /

UK / ʃʊr /

A1
  • adjecitve
  • Having no doubts about something
  • Have confidence in your own words or actions
  • Firmly established or held; being firm or stable
  • Being correct or true
  • adverb
  • What you say to agree willingly

carbon

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US / 'kɑ:bən /

UK / ˈkɑrbən /

B1
  • noun
  • Chemical element with an atomic number of 6

concern

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US / kənˈsɜ:n /

UK / kənˈsɚn /

A2
  • noun
  • Company, firm or business
  • Feeling of worry or anxiety
  • verb
  • To be about a particular topic
  • To have a direct impact on someone
  • To be responsible or mixed up in; to be involved
  • To feel worry or anxiety

feel

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US / fi:l /

UK / fil /

A1
  • verb
  • To be aware of or experience an emotion, sensation
  • To sense through direct contact; touch

equivalent

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US / ɪˈkwɪvələnt /

UK / ɪˈkwɪvələnt /

B1
  • adjecitve
  • Equal to something in value, use or meaning
  • noun
  • Thing like another in quality, quantity or degree

himself

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US / hɪmˈself /

UK / hɪmˈsɛlf /

A1
  • pronoun
  • The same (male) person who did the action

retain

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US / rɪ'teɪn /

UK / rɪˈten /

A2
  • verb
  • To continue to have or use; keep the quality of
  • To keep one thing inside another for a time
  • To memorize information

reason

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US / 'ri:zn /

UK / ˈrizən /

A1
  • noun
  • Ability to think about facts and form a judgment
  • Explanation for why something occurred or was done
  • verb
  • To think and make conclusions in a logical manner

side

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US / saɪd /

UK / saɪd /

A1
  • adjecitve
  • In addition to the central or most important thing
  • Next to, or very close to, the right or left of
  • noun
  • Position or opinion that is opposite to another
  • Right or left part of a person's body
  • Feature of someone's personality
  • Straight edge of an object
  • One of two or more groups fighting each other
  • verb
  • To decide to agree with one point, not the other

roosevelt

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US / ˈrəʊzəvɛlt /

UK / ˈroʊzəˌvɛlt /

A1

too

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US / tu: /

UK / tu /

A1
  • adverb
  • In addition, also; with emphasis
  • Say that something is more than you want

four

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US / fɔ:(r) /

UK / fɔr, for /

A1
  • number
  • 4

matter

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US / 'mætə(r) /

UK / ˈmætɚ /

A1
  • noun
  • Material all things are made of that fills space
  • Problem or reason for concern
  • verb
  • To be of great importance; to count

once

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US / wʌns /

UK / wʌns /

A1
  • adverb
  • One time; one instance
  • At a time in the past
  • conjunction
  • When; as soon as

practically

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US / ˈpræktɪkli /

UK / ˈpræktɪkli /

C1
  • adverb
  • Nearly, almost, or in effect

wait

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US / weɪt /

UK / wet /

A1
  • verb
  • To delay or not do something until later
  • To spend time until an expected thing happens
  • To remain in a place until a thing happens

after

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US / 'ɑ:ftə(r) /

UK / ˈæftɚ /

A1
  • adverb
  • Later than another time, or behind something
  • conjunction
  • Following something before
  • preposition
  • When an event happened or time has passed

always

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US / 'ɔ:lweɪz /

UK / ˈɔlwez,-wɪz,-wiz /

A1
  • adverb
  • For a very long time
  • At all times; in every situation
  • For ever

already

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US / ɔ:lˈredi /

UK / ɔlˈrɛdi /

A1
  • adverb
  • Having happened or been done before this time

liquid

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US / ˈlɪkwɪd /

UK / ˈlɪkwɪd /

A2
  • adjecitve
  • (Of wealth) being able to be spent as cash
  • In a state of being uncertain
  • Moving in a flowing manner, like water or oil
  • noun
  • Something that is similar to the state of water

regulate

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US / ˈregjuleɪt /

UK / ˈrɛɡjəˌlet /

A2
  • verb
  • To control something with rules or laws
  • To set/adjust (a clock, etc.); restrict motion in

spontaneously

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US / spɒn'teɪnɪəslɪ /

UK / spɔnˈtenɪəslɪ /

B1
  • adverb
  • In a sudden, unplanned way

thousand

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US / ˈθaʊznd /

UK / ˈθaʊzənd /

A1
  • number
  • Number 1,000

will

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US / wɪl /

UK / wɪl /

A1
  • noun
  • Desire or choice of someone
  • Document saying who gets your money when you die
  • Strong desire to do something; determination
  • Desire to do something; strong wish to do
  • other
  • Used with verbs to express the future
  • verb
  • To leave property to someone after your death
  • To use mental effort to make something happen
  • Am (is, are) likely to do
  • To influence someone to do something
  • To make something happen by strongly wanting it

atom

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US / 'ætəm /

UK / ˈætəm /

B1
  • noun
  • Smallest bit that matter can be broken down into

between

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US / bɪˈtwi:n /

UK / bɪˈtwin /

A1
  • preposition
  • From one person, thing, or place, to another
  • In the space that separates two objects
  • Among two or more people who share something

kiloton

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US / 'kɪlətʌn /

UK / 'kɪləˌtʌn /

A1
  • noun
  • One thousand ton

pursue

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US / pə'sju: /

UK / pɚˈsu /

B1
  • verb
  • To follow and try to catch, or to reach a goal
  • To try to achieve or get something over time

sleep

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US / sli:p /

UK / slip /

A1
  • noun
  • Substance in a person's eyes after waking up
  • Period of time during which a person is asleep
  • verb
  • To have enough beds for
  • To rest your body in bed, as at night time

they

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US / ðeɪ /

UK / ðe /

A1
  • pronoun
  • Two or more people, animals, or things

very

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US / 'verɪ /

UK / ˈvɛri /

A1
  • adjecitve
  • Concerning a large degree or amount
  • adverb
  • A lot; much; many
  • Used to stress or emphasize a noun

eighteen

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US / ˌeɪˈti:n /

UK / eˈtin /

A1
  • number
  • 18

einstein

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US / ˈaɪn.staɪn /

UK / ˈaɪn.staɪn /

A1
  • noun
  • Albert Einstein, a German-born theoretical physicist

heavy

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US / 'hevɪ /

UK / ˈhɛvi /

A1
  • adjecitve
  • Greater in amount, degree, or severity than usual
  • Involving serious or strong emotions
  • Having a lot of weight

gain

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US / ɡeɪn /

UK / ɡen /

A2
  • noun
  • An increase in something, such as weight
  • verb
  • To increase in something, such as weight
  • To get something wanted, needed or valued

work

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US / wɜ:k /

UK / wɚk /

A1
  • adjecitve
  • Activity completed in order to make money
  • noun
  • The product of some artistic or literary endeavor
  • Everything created by an author, artist, musician
  • Activity you do in order to make money
  • Place of employment
  • Final product or result of a some labor or effort
  • verb
  • To bring into a specific state of success
  • To be functioning properly, e.g. a car
  • To do your job in your company or workplace
  • To make an effort to do something
  • To operate a machine or device

bit

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US / bɪt /

UK / bɪt /

A1
  • noun
  • Device put in a horse's mouth to control it
  • Small piece of something
  • verb
  • (E.g. of fish) to take bait and be caught

hiroshima

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US / /

UK / /

A1
  • proper noun
  • A city in southwestern Japan, on the southern coast of the island of Honshu; population 1,144,572 (2

nice

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US / naɪs /

UK / naɪs /

A1
  • adjecitve
  • Being attractive or of high quality or value
  • Good or enjoyable
  • Being kind or friendly

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

human

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US / 'hju:mən /

UK / ˈhjumən /

A1
  • adjecitve
  • Concerning or characteristic of people
  • noun
  • A person; a man, woman or child

tap

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US / tæp /

UK / tæp /

A2
  • noun
  • Faucet; the place you can get water from a pipe
  • Light hit, generally one that makes a sound
  • verb
  • To access a liquid (e.g. in a tree) through a hole
  • To move feet/fingers to make light regular sounds
  • To spy one someone electronically
  • To hit something or someone lightly
  • To remove from an object e.g. oil from the ground

wreak

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US / ri:k /

UK / rik /

C1
  • verb
  • To cause something damaging or violent to happen

annihilation

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US / əˌnaɪə'leɪʃn /

UK / əˌnaɪəˈleʃən /

C1
  • noun
  • Total destruction

change

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US / tʃeɪndʒ /

UK / tʃendʒ /

A1
  • noun
  • Exchange of one set of clothes for another
  • Money in the form of coins instead of paper
  • Money returned after giving too much
  • Act of making or becoming something else
  • verb
  • To exchange one set of clothes for another
  • To exchange one kind of money for another
  • To replace something with another thing
  • To make or become something else
  • To go from one train, bus, etc. and go to another

pressure

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US / 'preʃə(r) /

UK / ˈprɛʃɚ /

A2
  • noun
  • Anxiety caused by difficult problems
  • Force, weight when pressing against a thing
  • Strong persuasion to do something
  • verb
  • To apply force to something
  • To persuade or force someone to do something

fusion

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US / ˈfju:ʒn /

UK / ˈfjuʒən /

B2
  • noun
  • Combining various things to make something new

simple

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US / 'sɪmpl /

UK / ˈsɪmpəl /

A1
  • adjecitve
  • Not hard to understand or do; not complex
  • Having only a few parts; not complex
  • Being ordinary or normal
  • Being plain; without a lot added for style

show

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US / ʃəʊ /

UK / ʃo /

A1
  • noun
  • False display of love, emotion or action
  • An event for displaying or promoting goods
  • Play, opera or theater production
  • Presentation that is broadcast on TV or radio
  • verb
  • To be easily seen or displayed
  • To display your emotions or feelings
  • To let someone see something; display
  • To explain or teach how something is done
  • To lead someone somewhere; point them to something
  • To prove something to be true, correct
  • To reveal or allow something to be seen

guarantee

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US / ˌɡærən'ti: /

UK / ˌɡærənˈti /

A2
  • noun
  • A promise to repair a broken product
  • Promise that something will be done as expected
  • verb
  • To promise to repair a broken product
  • To promise that something will happen or be done
  • To promise to pay if another person fails to do so

move

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US / mu:v /

UK / muv /

A1
  • noun
  • Act of moving a playing piece in chess, etc.
  • An action; doing something
  • Step taken to achieve a goal
  • verb
  • To cause someone to have certain emotions
  • To cause something to change to a different place
  • To change where people live or a business operates
  • To take action to do or achieve something

yes

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US / jes /

UK / jɛs /

A1
  • adverb
  • Way to say you agree or will do something

way

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US / weɪ /

UK / we /

A1
  • adverb
  • Used to emphasize the amount of something
  • noun
  • Particular aspect of something being thought about
  • One of various choices that could be made
  • Particular existing condition or state
  • (Often long) distance or length of time
  • How something is done
  • Route to go to a place
  • Small street
  • Usual behavior, emotions or habits of someone

drop

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US / drɒp /

UK / drɑp /

A1
  • noun
  • Distance between a higher and a lower level
  • Act of letting something fall (from your hand)
  • A decrease in quantity or quality; reduction
  • Tiny amount of liquid, with rounded bottom
  • verb
  • To drive someone to a place and then drive away
  • To let something fall from your hand
  • To fall or lie down quickly, as when shot
  • To decide to stop something e.g. a course)
  • To (cause to) reduce in quantity or quality

its

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US / ɪts /

UK / ɪts /

A1
  • adjecitve
  • Referring to or belonging to ‘it’
  • determiner
  • Of something; belonging or related to something
  • other
  • Possessive form of “it”

who

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US / hu: /

UK / hu /

A1
  • pronoun
  • Which person
  • Used to introduce information about people

whore

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US / hɔ:(r) /

UK / hɔr, hor /

A1
  • verb
  • To work as a prostitute

top

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US / tɒp /

UK / tɑp /

A1
  • adjecitve
  • Being good or great; excellent
  • Being the most in degree or quality
  • noun
  • Item of clothing covering shoulders to waist, hips
  • A cover or lid
  • Part (e.g. road) that is the furthest away
  • Highest or upper part or point of something
  • Best or highest status or position
  • Flat upper surface or edge of an object
  • Child's toy that spins on its point
  • Upper section or leaves of fruits and vegetables
  • Winning in a sport or contest
  • verb
  • To be higher or larger than a specific value
  • To arrive at the highest point of something
  • To put a cover or layer or over something
  • To kill; murder
  • To hold the highest position on a list
  • To be more important, successful or better than
  • To beat someone or win at a game

bathe

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US / beɪð /

UK / beð /

B1
  • verb
  • To be covered completely in something, e.g. light
  • To swim at the beach or in a river
  • To wash yourself or others in a bath

bring

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US / brɪŋ /

UK / brɪŋ /

A1
  • verb
  • To take or go with someone to a place

geopolitic

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US / ˌdʒɪˈəʊpəˈlɪtɪk /

UK / /

C2
  • noun
  • Study of relationship among politics and geography

movie

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US / ˈmu:vi /

UK / ˈmuvi /

A1
  • noun
  • Motion picture; film

project

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US / prəˈdʒekt /

UK / prəˈdʒɛkt /

A1
  • noun
  • A planned piece of work for specific purpose
  • Group of homes built by government for poor people
  • verb
  • To predict what will happen in the future
  • To show something on a screen using light
  • To stick out past the edge of something

self

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US / self /

UK / sɛlf /

A1
  • noun
  • Person's own interests or desires
  • Person that someone really is
  • Particular aspect of someone's personality
  • Person, usually someone already been mentioned

take

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US / teɪk /

UK / tek /

A1
  • noun
  • Filming of a single scene for TV or the movies
  • verb
  • To accept something that is offered
  • To use a method of traveling, e.g. a bus or train
  • To use a camera to make (a photo)
  • To pick up something and go away with it
  • To study a subject in school
  • To attempt to pass (an exam)
  • To require a certain amount of time, money, space

account

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US / ə'kaʊnt /

UK / əˈkaʊnt /

A1
  • noun
  • An advantage
  • Arrangement with a bank to keep your money for you
  • An invoice for things bought
  • Arrangement whereby you can use online services
  • A description, often written, of events; report

dense

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US / dens /

UK / dɛns /

B1
  • adjecitve
  • Very thick and difficult to see, get through
  • Hard to understand
  • Uncomprehending; foolish; inconsiderate

main

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US / meɪn /

UK / men /

A1
  • adjecitve
  • Most important; most often used

possible

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US / ˈpɒsəbl /

UK / ˈpɑsəbəl /

A1
  • adjecitve
  • Being able or appropriate for a task or purpose
  • Having a chance of happening, or being true

speed

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US / spi:d /

UK / spid /

A2
  • noun
  • How fast or slow something is or is done
  • verb
  • To move quickly when completing an action
  • To drive a vehicle faster than laws allow

become

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US / bɪ'kʌm /

UK / bɪˈkʌm /

A1
  • verb
  • To begin to be; grow to be; develop into
  • To be suitable for a particular job or role

periodic

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US / ˌpɪəriˈɒdɪk /

UK / ˌpɪriˈɑ:dɪk /

A2
  • adjecitve
  • Happening regularly, but not frequently

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

sixteen

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US / ˌsɪksˈti:n /

UK / sɪkˈstin /

A1
  • number
  • 16

slow

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US / sləʊ /

UK / sloʊ /

A1
  • adjecitve
  • Lacking activity, busyness or excitement
  • (Clock) showing time earlier than the actual time
  • Having difficulty understanding simple things
  • Moving or happening without speed; not fast
  • verb
  • To move, with less speed than before
  • To move or go without much speed

bunker

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US / ˈbʌŋkə(r) /

UK / ˈbʌŋkɚ /

B2
  • noun
  • Section of a golf course that contains sand

maybe

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US / ˈmeɪbi /

UK / ˈmebi /

A1
  • adverb
  • Possibly but not certainly; perhaps

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

mine

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US / maɪn /

UK / maɪn /

A1
  • noun
  • A bomb hidden in the ground or the sea
  • Rich source of material or information
  • Place under the ground where coal, etc. is dug out
  • pronoun
  • That thing that belongs to me
  • verb
  • To place a bomb in the ground or the sea
  • To dig into the earth or sea to obtain minerals

powerful

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US / ˈpauəful /

UK / ˈpaʊəfəl /

A2
  • adjecitve
  • Having control or influence over
  • Having a lot of physical force, energy, strength

size

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US / saɪz /

UK / saɪz /

A1
  • noun
  • How big or small a thing is
  • Standard measurements for clothing, shoes
  • verb
  • To make something to fit a particular measurement
  • To organize or group from small to large

our

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US / 'aʊə(r) /

UK / aʊr /

A1
  • determiner
  • Belonging to us

civilization

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US / ˌsɪvəlaɪ'zeɪʃn /

UK / ˌsɪvəlɪˈzeʃən /

B2
  • noun
  • A highly developed society

gun

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US / ɡʌn /

UK / ɡʌn /

A2
  • noun
  • Weapon which fires bullets down a tube
  • verb
  • To suddenly make an engine run faster

havoc

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US / ˈhævək /

UK / 'hævək /

B2
  • noun
  • Situation with destruction, damage and confusion

ish

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US / ɪʃ /

UK / ɪʃ /

A1
  • abbreviation
  • ISH is an acronym

projectile

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US / prəˈdʒektaɪl /

UK / prəˈdʒɛktəl, -ˌtaɪl /

C1
  • noun
  • Something thrown or fired at a target

really

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US / ˈri:əli /

UK / ˈriəˌli, ˈrili /

A1
  • adverb
  • Used to stress something that is said; definitely
  • In a true or accurate manner
  • Very

thermo

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US / ˈθɜːməʊ /

UK / ˈθɜrmoʊ /

A1
  • noun
  • Thermostat

tnt

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US / ˌtiː en ˈtiː /

UK / ˌtiː en ˈtiː /

A1
  • noun
  • Explosive material

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

brother

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US / ˈbrʌðə(r) /

UK / ˈbrʌðɚ /

A1
  • noun
  • A boy or man who shares a parent with you

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

nearly

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US / ˈniəli /

UK / ˈnɪrli /

A1
  • adverb
  • Not completely; almost

war

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US / wɔ:(r) /

UK / wɔr /

A2
  • noun
  • Situation where armies fight each other

convert

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US / kən'vɜ:t /

UK / kənˈvɚt /

A2
  • noun
  • Person switching from one belief system to another
  • verb
  • To switch from a religion, belief etc. to another
  • To change form, character, or function to another

equal

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US / 'i:kwəl /

UK / ˈikwəl /

A1
  • adjecitve
  • Same in shape, size, or number
  • verb
  • To add up or be the same as

neat

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US / ni:t /

UK / nit /

A2
  • adjecitve
  • That you approve of; cool
  • (Of alcohol) not weakened with water or a mixer
  • Not messy; clean and orderly; simple and effective

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

sight

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US / saɪt /

UK / saɪt /

A2
  • noun
  • Things or people that one can see
  • Range or distance that someone can see
  • Famous places often visited by tourists
  • Sense that allows you to see
  • Act of seeing someone or something
  • verb
  • To aim (a gun) at something to get your range
  • To see something rare or unusual

skim

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US / skɪm /

UK / skɪm /

B1
  • verb
  • To remove fat, etc. from the top of a liquid
  • To read rapidly to find the main points or ideas
  • To fly over a surface without touching it

table

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US / ˈteɪbl /

UK / ˈtebəl /

A1
  • noun
  • Diagram that shows data in rows and columns
  • Raised flat surface you sit at to work or eat
  • verb
  • To leave an idea to be discussed at a later date

business

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US / ˈbɪznəs /

UK / ˈbɪznɪs /

A1
  • noun
  • A company formed for making profit
  • Matter that has to be dealt with; task; situation
  • Activity of working to make a profit

pleasure

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US / 'pleʒə(r) /

UK / ˈplɛʒɚ /

A2
  • noun
  • Feeling of happiness, enjoyment, or satisfaction

philosophically

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US / ˌfɪlə'sɒfɪklɪ /

UK / ˌfɪləˈsɑfɪkl:ɪ /

C1
  • adverb
  • In a calm, reasonable way, even if things are bad

whether

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US / ˈweðə(r) /

UK / ˈhwɛðɚ, ˈwɛð- /

A1
  • conjunction
  • If something will happen or not

especially

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US / ɪˈspeʃəli /

UK / ɛˈspɛʃəli, ɪˈspɛʃ- /

A1
  • adverb
  • More than usual; extremely

good

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US / ɡʊd /

UK / ɡʊd /

A1
  • adjecitve
  • Proper, appropriate or right
  • (Of an amount) enough; plenty
  • Excellent; high quality
  • Acting well or properly; of moral character
  • In a positive or happy emotional state
  • noun
  • Advantage or benefit

fifty

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US / 'fɪftɪ /

UK / ˈfɪfti /

A1
  • number
  • 50

life

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US / laɪf /

UK / laɪf /

A1
  • noun
  • All the living things e.g. animals, plants, humans
  • Period of time things live, from birth to death

underground

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US / ˈʌndəgraʊnd /

UK / ˈʌndərgraʊnd /

B1
  • adjecitve
  • (Being or living) under the surface of the earth
  • noun
  • Secret group organized to overthrow a government
  • Subway system, e.g. in London

craze

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US / kreɪz /

UK / krez /

B2
  • noun
  • Popular or widespread fad, fashion, etc.

helium

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US / ˈhi:liəm /

UK / ˈhiliəm /

C1
  • noun
  • Light, colorless gaseous element with no smell

fission

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US / ˈfɪʃn /

UK / ˈfɪʃən /

C1
  • noun
  • Form of nuclear energy where particles combine

sum

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US / sʌm /

UK / sʌm /

A2
  • noun
  • Amount when all is added together; total
  • verb
  • To add two or more numbers together; total

want

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US / wɔnt /

UK / wɑnt, wɔnt /

A1
  • noun
  • Something you desire or wish for
  • State or condition of poverty
  • verb
  • To desire or wish for something; hope for a thing

anything

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US / ˈeniθɪŋ /

UK / ˈɛniˌθɪŋ /

A1
  • pronoun
  • A thing of any kind

escape

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US / ɪ'skeɪp /

UK / ɪˈskep /

A2
  • noun
  • Act to briefly ignoring boring or bad things
  • The 'esc key' on a keyboard
  • Act of getting away from where you are being kept
  • verb
  • To avoid something undesirable, dangerous or bad
  • To get away from a place where you are being kept
  • (Gas, water) to come out from a pipe, container
  • To not to be noticed or remembered by someone

from

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US / frəm /

UK / frʌm, frɑm,frəm /

A1
  • preposition
  • Starting at a particular place, time or level

hot

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US / hɒt /

UK / hɑ:t /

A1
  • adjecitve
  • Angry or excited
  • Being very good at something
  • Having a high temperature
  • Popular and causing a great deal of excitement
  • Attractive in a sexually exciting way
  • (Of food) very spicy
  • Stolen; dangerous to buy or trade in

over

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US / 'əʊvə(r) /

UK / ˈovɚ /

A1
  • adverb
  • Finished; no longer happening
  • Towards the ground/away from a standing position
  • noun
  • A set of six consecutive balls bowled in cricket
  • other
  • Finished
  • preposition
  • Showing the relation when a thing is above another
  • On or covering something
  • Above or across something
  • More than you need
  • From one side to the other
  • In the direction of; toward

temperature

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US / ˈtemprətʃə(r) /

UK / ˈtɛmpərəˌtʃʊr,-tʃɚ,ˈtɛmprə- /

A2
  • noun
  • When you your body heat is above normal
  • How hot or cold something is, e.g. the weather

another

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US / əˈnʌðə(r) /

UK / əˈnʌðɚ /

A1
  • adjecitve
  • One more, but not this
  • determiner
  • One more added
  • pronoun
  • One more (thing)

hey

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US / heɪ /

UK / he /

A1
  • exclamation
  • What you say when you want someone's attention

warmth

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US / wɔ:mθ /

UK / wɔ:rmθ /

A1
  • noun
  • Quality of kindness, friendliness, or sincerity
  • A friendly manner
  • State of being warm but not hot or cold

blast

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US / blɑ:st /

UK / blæst /

B1
  • noun
  • Destructive wave of air from an explosion
  • Strong current of wind
  • verb
  • To attack someone with words
  • To destroy something with explosives
  • To make a loud noise on or with something

finally

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US / ˈfaɪnəli /

UK / ˈfaɪnəli /

A1
  • adverb
  • used especially at the beginning of a sentence to introduce the last point or idea
  • After a long time or some difficulty

fissionable

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US / ˈfɪʃənəbəl /

UK / ˈfɪʃnəbl /

A1
  • adjecitve
  • Capable of undergoing nuclear fission

ignite

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US / ɪɡ'naɪt /

UK / ɪɡˈnaɪt /

B2
  • verb
  • To catch fire
  • To cause something to start burning
  • To give energy to something or someone

forty

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US / 'fɔ:tɪ /

UK / ˈfɔrti /

A1
  • number
  • 40

keep

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US / ki:p /

UK / kip /

A1
  • noun
  • Large, strong tower in the middle of a castle
  • Money spent on you so you can live in a place
  • verb
  • To continue doing something; not to stop
  • To stop balls going in a goal in sports
  • To not give back or return something
  • (Of food) to not spoil or not rot
  • To take possession of something to own, e.g. a pet
  • To have and continue to hold something
  • To do something that you have promised or agreed
  • To stay in a certain place or condition
  • To maintain the rules

nineteen

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US / ˌnaɪnˈti:n /

UK / naɪnˈtin /

A1
  • number
  • 19

oppenheimer

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US / əˈpɪnjəneɪtɪd /

UK / əˈpɪnjəˌnetɪd /

A1

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

version

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US / ˈvə:ʃən /

UK / ˈvɚʒən, -ʃən /

A2
  • noun
  • Different way that someone interprets something
  • New or different form of something
  • An updated form of some software

ban

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US / bæn /

UK / bæn /

B1
  • noun
  • Official action preventing something happening
  • verb
  • To make something illegal or not allowed

chuck

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US / tʃʌk /

UK / tʃʌk /

B2
  • noun
  • Person's name
  • verb
  • To throw carelessly or casually

early

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US / ˈɜ:li /

UK / ˈɜ:rli /

A1
  • adjecitve
  • Happening or appearing before
  • adverb
  • Coming/happening before others in a time sequence
  • Happening sooner than expected

frightening

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US / ˈfraɪtnɪŋ /

UK / ˈfraɪtnɪŋ /

A2
  • adjecitve
  • Being scary
  • verb
  • To make someone afraid or nervous

rest

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US / rest /

UK / rɛst /

A1
  • noun
  • Time when one relaxes, sleeps, or is inactive
  • State in which there is a lack of motion
  • Part of something remaining after some was used
  • verb
  • To stop working or avoid activity to recover
  • (Of dead person) to lie in a grave
  • To lean, support or place something against
  • To not be tired because you had enough sleep

back

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US / bæk /

UK / bæk /

A1
  • adjecitve
  • Farthest from the front e.g. in a classroom
  • adverb
  • Have returned to a place you were before
  • noun
  • The part of a chair that the upper body leans upon
  • Location at the rear of something
  • The reverse of side something
  • Area on the rear of your body
  • verb
  • To bet money on something
  • To go backwards in a car
  • To support and encourage someone or some cause

calculation

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US / ˌkælkjuˈleɪʃn /

UK / ˌkælkjəˈleʃən /

B2
  • noun
  • Process or result of using mathematics
  • An educated guess about something

ledger

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US / 'ledʒə(r) /

UK / ˈlɛdʒɚ /

B2
  • noun
  • Book containing accounting records

manhattan

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US / mæn'hætn /

UK / mæn'hætn: /

A1
  • noun
  • A cocktail made with whiskey and sweet vermouth with a dash of bitters
  • other
  • One of the five boroughs of New York City

lot

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US / lɒt /

UK / lɑt /

A1
  • noun
  • What happens to a person in life from chance; fate
  • A group of people seen together
  • Item for sale at an auction
  • Small area of land used for a purpose e.g. parking

until

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US / ənˈtɪl /

UK / ʌnˈtɪl /

A1
  • conjunction
  • Up to; to a time when something happens
  • preposition
  • Before (a specific time)

come

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US / kʌm /

UK / kʌm /

A1
  • verb
  • To arrive at a place
  • (Of mail) to be delivered
  • To move toward someone; go with someone
  • To reach a certain point or state

effort

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US / ˈefət /

UK / ˈɛfət /

A2
  • noun
  • Amount of work used trying to do something

isotope

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US / ˈaɪsətəʊp /

UK / ˈaɪsətoʊp /

A1
  • noun
  • Chemical element nearly identical, but with differing weights

match

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US / mætʃ /

UK / mætʃ /

A2
  • noun
  • Something that is equal to or the same as another
  • Small stick you strike to light a fire candle etc.
  • A sports competition between two people or teams
  • Person or thing that goes well with another
  • verb
  • To equal or be as good as something else
  • To work well or look good with something else

megaton

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US / ˈmegətʌn /

UK / ˈmɛɡəˌtʌn /

C2
  • noun
  • One million tons of TNT

literally

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US / ˈlɪtərəli /

UK / ˈlɪtərəli /

B1
  • adverb
  • So as to express the exact meaning of something
  • Used to say something is true, even if unlikely

risky

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US / ˈrɪski /

UK / ˈrɪski /

A2
  • adjecitve
  • With the chance it may be dangerous, unsuccessful

think

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US / θɪŋk /

UK / θɪŋk /

A1
  • verb
  • To have an idea about something without certainty
  • To have an idea, opinion or belief about something

wave

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US / weɪv /

UK / wev /

A2
  • noun
  • Movement of sound, air or energy
  • Deep and strong emotion that is suddenly felt
  • Slightly curved shape in hair
  • Frequency of movement of objects together
  • Up and down movement of water in a lake or sea
  • Signal with your hand to say hello or goodbye
  • verb
  • To cause to move side to side or back and forth
  • To swing back and forth as a result of the wind
  • To move your hand or arm to say hello or goodbye

clean

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US / kli:n /

UK / klin /

A1
  • adjecitve
  • Not marked in any way; blank
  • Done according to the rules or standards; fair
  • Free from disease or sickness
  • Being free from dirt or marks; washed
  • Behaving well; not breaking any rules; legal
  • adverb
  • Completely; entirely
  • verb
  • To make free from dirt or marks; washed
  • To make neat and orderly e.g. a room
  • To remove the inner parts of an animal

completely

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US / kəmˈpli:tli /

UK / kəmˈpliːtli /

A1
  • adverb
  • In every way or as much as possible

electron

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US / ɪˈlektrɒn /

UK / ɪˈlektrɑ:n /

B2
  • noun
  • A negatively charged particle

incinerate

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US / ɪnˈsɪnəreɪt /

UK / ɪnˈsɪnəˌret /

C1
  • verb
  • To burn, especially to burn completely

only

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US / ˈəunli /

UK / ˈonli /

A1
  • adverb
  • Just one; just that amount or thing; not more than
  • Not very important or serious
  • Just that type of thing, person
  • Short time ago; not before a certain time
  • conjunction
  • Except; but

put

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US / pʊt /

UK / pʊt /

A1
  • phrasal verb
  • to make a light stop shining by pressing or moving a switch
  • verb
  • To move or place a thing in a particular position
  • To rate something in importance or value
  • To write or say something in a certain manner

release

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US / rɪ'li:s /

UK / rɪ'li:s /

A2
  • noun
  • Act of freeing someone from a duty or burden
  • Introduction of a new product, film, book, etc.
  • Relief from sadness, suffering or trouble
  • Act of freeing from a jail, cage, prison, etc.
  • verb
  • To free someone from a responsibility or burden
  • To allow a film, music etc. to be sold/distributed
  • To allow to leave a jail, cage, etc.; let out
  • To let go of something you are holding

two

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US / tu: /

UK / tu /

A1
  • number
  • 2

trigger

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US / 'trɪɡə(r) /

UK / ˈtrɪɡɚ /

B1
  • noun
  • Lever on a gun that you pull to fire
  • Device that starts a process
  • verb
  • To start a process off e.g. a memory

ten

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US / ten /

UK / tɛn /

A1
  • number
  • 10

call

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US / kɔ:l /

UK / kɔl /

A1
  • noun
  • A order or request for action
  • The sound an animal makes, often when in danger
  • A correct prediction, e.g. a decision in a game
  • A short visit to a place or person
  • A decision by a referee or umpire in a game
  • verb
  • To make a request or order for action
  • (Animal) to make sounds to warn of danger
  • To announce the date of an election
  • To make a judgment about something
  • To give someone or something a name
  • To guess in advance the result or outcome
  • To visit a place or person for a short time
  • To phone someone
  • To speak, announce or shout in a loud voice

gunpowder

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US / ˈɡʌnpaʊdə(r) /

UK / ˈɡʌnpaʊdər /

C2
  • noun
  • Chemical used in fireworks, to fire cannon, etc.

far

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US / fɑ:(r) /

UK / fɑr /

A1
  • adjecitve
  • A long way away
  • Being a long way away
  • adverb
  • To a large degree or extent

nucleus

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US / ˈnju:kliəs /

UK / ˈnu:kliəs /

B2
  • noun
  • Center of an atom
  • Control center of a cell
  • Most important part of something larger

where

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US / hwɛə /

UK / hwɛr, wɛr /

A1
  • conjunction
  • At or in the place which
  • In whatever place
  • pronoun
  • Word you use to ask the location of something

for

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US / fə(r) /

UK / fɔr,fə /

A1
  • preposition
  • Used to show the purpose, or need of something

resort

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US / rɪ'zɔ:t /

UK / rɪ'zɔ:rt /

B1
  • noun
  • Act of choosing something to help with a problem
  • Vacation hotel or complex; area for holidays

through

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US / θru: /

UK / θru /

A2
  • adjecitve
  • having finished using or doing something
  • adverb
  • From the beginning of something until the end
  • preposition
  • Over, in, across an entire thing or place
  • Allowing you to pass between, or to
  • By a particular way or process; by the use of

treaty

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US / ˈtri:ti /

UK / ˈtriti /

B1
  • noun
  • An agreement between nations

why

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US / waɪ /

UK / hwaɪ, waɪ /

A1
  • adverb
  • Question word to ask for a reason
  • exclamation
  • (Used to express surprise or approval)

time

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US / taɪm /

UK / taɪm /

A1
  • noun
  • Speed at which music is played; tempo
  • Point as shown on a clock, e.g. 3 p.m
  • Number of hours, minutes needed to do something
  • Occasion when something happens
  • Period or occasion that something occurred
  • Period in history or the past
  • Something measured in minutes, hours, days, etc.
  • How long an event takes; duration
  • verb
  • To check speed at which music is performed
  • To choose a specific moment to do something
  • To measure how long an event takes, e.g. a race
  • To schedule something to occur at a specific moment

ask

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US / ɑ:sk /

UK / æsk /

A1
  • verb
  • To say to someone that you want something

limit

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US / 'lɪmɪt /

UK / ˈlɪmɪt /

A2
  • noun
  • Point beyond which it is not possible to go
  • verb
  • To stop or prevent an increase past a point

nuclear

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US / ˈnju:kliə(r) /

UK / ˈnukliɚ, ˈnju- /

A2
  • adjecitve
  • Concerning or involving the center of an atom

set

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US / set /

UK / sɛt /

A1
  • adjecitve
  • Prepared for something; ready
  • noun
  • Complete group of something
  • Place where a television show or movie is filmed
  • Group of games in a tennis match
  • Device that receives radio or television signals
  • verb
  • To make a clock state or ring at a particular time
  • To decide upon or choose something
  • To make something ready for use (e.g. table)
  • To decide on a price for something
  • To become hard (of glue, concrete etc.)
  • To be located in a specific place or time
  • To put (e.g. a vase) down carefully in a place
  • To put someone in a certain condition or state
  • (Of the sun) to go lower than the horizon

test

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US / test /

UK / test /

A1
  • noun
  • A medical examination
  • Action to establish the truth or nature of
  • Examination; questions to measure knowledge
  • verb
  • To be given a medical examination
  • To try to establish the truth or nature of
  • To ask a series of questions to measure knowledge

start

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US / stɑ:t /

UK / stɑrt /

A1
  • noun
  • First time or place that a thing exists; beginning
  • First opportunity to achieve something, e.g. a job
  • Sudden action or movement because you are scared
  • other
  • Beginning of something in place or time
  • verb
  • To do, be or happen for the first time; begin
  • To turn something on

gasoline

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US / ˈgæsəli:n /

UK / ˈɡæsəˌlin, ˌɡæsəˈlin /

B2
  • noun
  • Liquid we put in cars to make them run

well

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US / wel /

UK / wɛl /

A1
  • adjecitve
  • Being in a fortunate, good condition or state
  • Healthy and in good condition
  • adverb
  • In an acceptable, proper, or successful manner
  • In a complete, total, or full manner
  • A great and considerable degree
  • In a successful way, in a good or satisfactory way
  • exclamation
  • Used to begin or continue a particular statement
  • Used to show you want to start saying something
  • Used to express that you are waiting for a reply
  • You say this to change the topic of a conversation
  • Used to indicate you are making a final remark
  • noun
  • Long deep hole in the ground to get water
  • verb
  • To cause your eyes to fill with tears

atomic

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US / əˈtɒmɪk /

UK / əˈtɑ:mɪk /

B1
  • adjecitve
  • Concerning atoms

amount

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US / ə'maʊnt /

UK / əˈmaʊnt /

A1
  • noun
  • Quantity of something
  • verb
  • To add up to a certain figure

difference

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US / 'dɪfrəns /

UK / ˈdɪfərəns, ˈdɪfrəns /

A1
  • noun
  • A thing or issue that people do not agree about
  • Not of the same kind; unlike other things

disturbingly

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US / dɪ'stɜ:bɪŋlɪ /

UK / dɪ'stɜ:bɪŋlɪ /

B1
  • adverb
  • In a worrying way

send

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US / send /

UK / sɛnd /

A1
  • verb
  • To cause to behave or respond in a particular way
  • To cause mail or packages to go to another place
  • To move something quickly in a particular way
  • To give information or greetings to someone

stable

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US / 'steɪbl /

UK / ˈstebəl /

A2
  • adjecitve
  • In a position where something does not fall over
  • Having a chemical state that is not easily changed
  • Reacting in an even way; having good mental health
  • In good condition, and not likely to deteriorate
  • noun
  • Group of racing horses that belong to one owner
  • verb
  • To put horses in a stable

just

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US / dʒʌst /

UK / dʒʌst /

A1
  • adjecitve
  • Proper or appropriate; as is deserved
  • Doing or being what is right or fair
  • Legally correct; having enough evidence
  • adverb
  • Almost; nearly
  • Exactly at the time of
  • Exactly (the same as, like)

letter

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US / 'letə(r) /

UK / ˈlɛtɚ /

A1
  • noun
  • One of the 26 parts of the English alphabet
  • Message you put in an envelope and send by post

line

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US / laɪn /

UK / laɪn /

A1
  • noun
  • Border that divides two places or regions
  • Long crease in the skin, often from age
  • Mark that is long, straight and very thin
  • Row of words, letters or numbers that are written
  • Telephone connection
  • People waiting one behind the other; queue
  • Long thin wire, e.g. for electrical signal
  • verb
  • To put material along the inside of something

proton

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US / ˈprəʊtɒn /

UK / ˈproʊtɑ:n /

B2
  • noun
  • Tiny part of atom with positive electrical charge

report

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US / rɪ'pɔ:t /

UK / rɪˈpɔrt, ˈport /

A1
  • noun
  • Account of the necessary facts and information
  • The telling of news in the media
  • Official statement about something
  • verb
  • To submit a report or bill to the government
  • To write in a newspaper or speak on a news program
  • To state something officially
  • To officially present yourself to an authority
  • To describe something by telling it to others

quantum

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US / ˈkwɒntəm /

UK / ˈkwɑ:ntəm /

B2
  • noun
  • The smallest unit or amount of energy

talk

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US / tɔ:k /

UK / tɔk /

A1
  • noun
  • Style of speaking
  • Discussion between two countries
  • Giving information in front of people; lecture
  • Saying things or ideas to someone with words
  • verb
  • To make a formal speech about something
  • To say things or ideas to someone with words

asphalt

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US / ˈæsfælt /

UK / ˈæsfɔ:lt /

C1
  • noun
  • Hard mixture used to make roads and streets

cold

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US / kəʊld /

UK / kold /

A1
  • adjecitve
  • Having a very low temperature
  • Being unfriendly or lacking emotion
  • noun
  • Illness of sneezing, coughing, and a sore throat

capable

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US / 'keɪpəbl /

UK / ˈkepəbəl /

A2
  • adjecitve
  • Being able to do something very well; proficient

ocean

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US / 'əʊʃn /

UK / ˈoʃən /

A2
  • noun
  • Large body of salt water; a large sea

much

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US / mʌtʃ /

UK / mʌtʃ /

A1
  • adjecitve
  • Very; to a high level or degree
  • adverb
  • A lot; large amount; a high degree of
  • Nearly; basically
  • On many occasions; often
  • noun
  • A large amount; a great quantity

probability

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US / ˌprɒbəˈbɪləti /

UK / ˌprɑ:bəˈbɪləti /

A2
  • noun
  • What the chances are that something will happen

positive

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US / ˈpɒzətɪv /

UK / ˈpɑzɪtɪv /

A2
  • adjecitve
  • Showing agreement or support for something
  • Being sure about something; knowing the truth
  • Having the charge produced by electrons
  • Being good or useful
  • Showing that a chemical is present in a test

under

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US / ˈʌndə(r) /

UK / ˈʌndɚ /

A1
  • adjecitve
  • In the same place as another thing, but lower
  • adverb
  • In a lower quantity or price than expected
  • preposition
  • According to the terms of an agreement or law
  • Managed or controlled by the authority of
  • Being of a lesser quality or amount than expected
  • Influenced or affected by something or someone
  • Less or lower in age, amount, size or number

amazing

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US / ə'meɪzɪŋ /

UK / ə'meɪzɪŋ /

A2
  • adjecitve
  • Surprising in a pleasing way
  • verb
  • To cause wonder; to surprise completely

charge

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US / tʃɑ:dʒ /

UK / tʃɑrdʒ /

A2
  • noun
  • An attack by running quickly toward someone
  • A price for a service or goods
  • When a battery has a certain amount of electricity
  • Amount of money you pay for a service
  • verb
  • To run quickly toward someone to attack them
  • To ask for money as a price for a service or goods
  • To put electricity in a battery
  • To give responsibility to take care of or manage
  • To state that someone has committed a crime

eight

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US / eɪt /

UK / et /

A1
  • number
  • 8

kim

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US / kɪm /

UK / kɪm /

A1

mass

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US / mæs /

UK / mæs /

B1
  • noun
  • Religious ceremony in some Christian churches
  • Large amount or number of something
  • Main or largest part of something
  • Large number of people considered as a whole
  • Amount of matter that an object has
  • verb
  • To gather people or things into a large group

sound

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US / saʊnd /

UK / saʊnd /

A1
  • adjecitve
  • Sensible, dependable and reliable
  • Unbroken or undisturbed, as of sleep
  • Firm or solid in structure
  • Sane; not mentally ill
  • Clearly reasoned; involving sense, good judgment
  • noun
  • Unique quality that characterizes a style of music
  • Waves traveling in air or water that can be heard
  • verb
  • To seem or appear to be, from what was said
  • To say in a clear deliberate manner
  • To make a noise, e.g. to ring a bell

water

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US / 'wɔ:tə(r) /

UK / ˈwɔtɚ, ˈwɑtɚ /

A1
  • noun
  • Clear liquid that forms the seas, rivers and rain
  • Large area such as an ocean or sea
  • verb
  • (Of the eyes) to produce tears
  • (Mouth) to become wet at the thought of nice food
  • To pour liquids onto a plant to keep it alive

define

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US / dɪ'faɪn /

UK / dɪˈfaɪn /

A2
  • verb
  • To explain the meaning of words
  • To set or mark the limits of something

emission

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US / iˈmɪʃn /

UK / ɪˈmɪʃən /

B2
  • noun
  • A substance (e.g. gas) released into the air

initiate

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US / ɪˈnɪʃ.i.eɪt /

UK / ɪˈnɪʃ.i.eɪt /

A2
  • verb
  • To cause something to begin
  • To allow someone into a group by a special ceremony

light

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US / laɪt /

UK / laɪt /

A1
  • adjecitve
  • Being bright making it easy to see; not dark
  • Being pale and lacking darkness of color
  • Not heavy; weighing only a little
  • adverb
  • Carrying few bags when traveling
  • noun
  • A source of energy that makes a room or area bright
  • Way in which something or someone is understood
  • verb
  • To cause something to burn; put a burning match to
  • To provide a way to see ahead

molecule

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US / ˈmɒlɪkju:l /

UK / ˈmɑlɪˌkjul /

B2
  • noun
  • Two or more atoms chemically combined

possibly

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US / ˈpɒsəbli /

UK / ˈpɑ:səbli /

A1
  • adverb
  • May be true or likely, but is uncertain

split

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US / splɪt /

UK / splɪt /

A2
  • adjecitve
  • No longer married or in a relationship
  • (Injured) by cutting it open, as in someone's lip
  • (Of a decision) when people cannot decide a winner
  • noun
  • Difference of opinion in a group causing a break
  • Separation or a break in something
  • verb
  • To become divided or broken along a straight line
  • To cause a cut in (lip, etc.)
  • To have difference of opinion in a group
  • To separate into two or more pieces
  • To divide something in an even or fair way

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

though

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US / ðəu /

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A1
  • adverb
  • Although, despite the fact that

vanishingly

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US / ˈvænɪʃɪŋli /

UK / ˈvænɪʃɪŋli /

B1
  • adverb
  • So as to disappear or approach zero

correct

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A2
  • adjecitve
  • Being suitable and appropriate for an occasion
  • True or accurate
  • verb
  • To fix a problem
  • To write marks on a piece of work to show mistakes
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equation

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US / ɪˈkweɪʒn /

UK / ɪˈkweʒən, -ʃən /

B1
  • noun
  • Mathematical statement showing things to be equal
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question

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UK / ˈkwɛstʃən /

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  • noun
  • Issue or problems you are dealing with
  • What you ask about; issue
  • verb
  • To ask for or try to get information
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positron

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US / ˈpɒzɪtrɒn /

UK / ˈpɑ:zɪtrɑ:n /

A1
  • noun
  • Elementary particle with positive charge; interaction of a positron and an electron results in annih
  • Subtitles section
  • Chuck, time for another StarTalk explainer.
  • Yeah.
  • Yeah, but I heard you have something neat and new.
  • What's that?
  • Well, it's, you know, all the Oppenheimer craze is happening right now.
  • And, you know, when you get down to the science of that, you're talking about fission and fusion.
  • Now, you know, so what is the difference between fission and fusion?
  • I mean, of course, I know.
  • I already know.
  • I'm just asking for all those people that are going to the movie and then... Oh, is it for other people?
  • Yeah, you know, there's a lot of people who go into the movie and they don't even know the difference between fission and fusion.
  • I'm just like, we should not allow those people to remain ignorant.
  • We should let those people know the difference between fission and fusion.
  • Okay, all right.
  • So the periodic table is a sequence of nuclear count of protons.
  • from hydrogen, which has one proton, helium, two protons, lithium, three protons.
  • You just count them up all the way, and you keep going.
  • OK.
  • It turns out
  • the nuclei of atoms store energy.
  • That's not much different, philosophically, from molecules storing energy.
  • So gasoline molecule stores energy.
  • It's just sitting there as this liquid, minding its own business.
  • Wait, you take a match, bada bing, you release the energy that was in the molecules.
  • Now that's a fire.
  • OK, so this idea that
  • There's energy to be released in the atom.
  • That's not so weird when you think about it.
  • Right, right.
  • Okay?
  • So the question is, how do you get access to this energy?
  • Out of the atom.
  • What we learned slowly in the late eighteen hundreds and early nineteen hundreds is that some atoms are not stable.
  • A version of uranium
  • is not stable.
  • When I say a version, it's one that has a different number of neutrons in the nucleus.
  • But it's still uranium, because it has nearly two protons in the nucleus.
  • So you can vary the number of neutrons, and those are called isotopes.
  • An isotope is the same atom, but different numbers of neutrons in the nucleus.
  • When you do that, they have slightly different properties.
  • So there's a version of uranium
  • that spontaneously breaks into two other atoms and releases energy.
  • So that's what we call radioactivity.
  • If an element is radioactive, it is splitting on its own and releasing energy and the thing that it's in will start feeling hot.
  • Okay?
  • So that splitting of an atom is called fission.
  • Fission.
  • Now let's go to the low end.
  • I can't break hydrogen, it's only one proton.
  • When you're at the low end, you can cram the elements together so that they make a heavier element.
  • When you do that, the mass of the heavier element is less.
  • than the sum of the parts.
  • Where did the mass go?
  • It must have been released as energy.
  • According to whose equation?
  • Einstein E equals mc squared.
  • There you go.
  • Energy and mass are equivalent.
  • If you lose mass through this phenomenon, you gain energy out the other side of the equation.
  • So I take four hydrogen atoms.
  • crammed them together to make a full blooded helium atom, which has two protons and two neutrons.
  • Why doesn't it have four protons?
  • Two of the protons turned into neutrons spontaneously.
  • Look at that.
  • That's what they did.
  • Oh, now wait a minute.
  • Didn't they have a positive charge?
  • And now you have a neutron that has, like, no charge?
  • What happened to the charge?
  • Did it just disappear?
  • What happened?
  • All the budgets are kept clean in the accounting ledgers of particle physics.
  • So a positive charge was retained by the emission of a positron, the antimatter version of an electron.
  • So a proton becomes a neutron and a positron.
  • Now a positron is antimatter.
  • So if you're antimatter, you are leading a very risky life in a universe of matter.
  • Because if you encounter an electron, you annihilate and become pure energy.
  • Right.
  • So not only does the nucleus release energy, because the mass has less mass, the two protons and two neutrons, you also get energy from the annihilation of the positron.
  • OK.
  • Make a long story simple.
  • You can take light atoms, cram them together, make heavier atoms, and energy gets released.
  • You can combine hydrogen to get helium.
  • You can combine helium to get carbon.
  • That is called thermo, it takes high energy to do this, nuclear, nucleus of an atom, fusion, you're bringing them together.
  • Thermonuclear fusion, light elements become heavier.
  • That's our sun.
  • Our sun does that.
  • That's what our sun does.
  • It converts hydrogen into helium, releasing energy, bathing us in warmth.
  • At the high end, you split atoms and they release energy, okay?
  • You wanna make a weapon that taps the energy of the nucleus.
  • OK.
  • Well, it takes very high temperature to fuse hydrogen.
  • The sun does it under high temperature and high pressure.
  • Right.
  • Meanwhile, uranium is falling apart for free.
  • It's doing it on its own.
  • On its own.
  • It's like, I'm uranium.
  • I'm just an energy whore, baby.
  • I don't care.
  • All on its own.
  • So it turns out, when uranium unstably splits, it releases a neutron.
  • Well, wait a minute.
  • Here's something interesting.
  • If it splits, did I wait around for the next atom to split?
  • Or can I force a split?
  • It turns out, if you do the equation, one splitting atom releasing a neutron can split another atom.
  • So if you split two, if two neutrons come out, that'll get split, and the dense enough, you don't want it escaping, the material has to be dense enough to guarantee it's gonna hit another atom.
  • Then you split that, and it goes from one to two to four to eight to sixteen, and you get a runaway chain reaction.
  • There you go.
  • Look, oh my God.
  • that's so that's what the bomb is calculated that damn and if you if you purify your isotope of uranium you cram it down and you initiate that with a trigger
  • You have an atomic bomb.
  • Look at that.
  • So it's, you're, you're looking at a tremendous release of energy from something very small.
  • Yes.
  • And it all happens all in instantaneously.
  • Correct.
  • Chain reaction.
  • Wow.
  • Yes.
  • Oh my God.
  • First of all, who,
  • How do you think of that?
  • He's your scientist.
  • That's what I'm saying.
  • He's my people.
  • He's my brethren.
  • Who even thinks of this?
  • Well, go back.
  • Who thought of a bow and arrow?
  • Who thought of gunpowder to put in a projectile?
  • There you go.
  • It just came out of a gun.
  • That's right.
  • Who thought of missiles?
  • Who thought of, like, let's go back, catapults, right?
  • You know, this is.
  • That's amazing.
  • Yeah, it's disturbingly amazing.
  • It's disturbingly amazing.
  • Correct.
  • Okay.
  • So you can get a certain amount of energy out of that, and it takes effort to purify the uranium, all right?
  • Because you need a uranium mine, and you've got to make sure there's just that one isotope, because only that one isotope will do this, not the other ones.
  • This is why you use centrifuges.
  • Why do you have a centrifuge?
  • Because one isotope is slightly more massive than the other.
  • And so you centrifuge it, and the heavier isotope goes to the bottom, and the lighter ones go to the top.
  • Then you skim off the top, centrifuge it again, and it becomes purer and purer and purer.
  • Did you see Top Gun Maverick?
  • No.
  • The main point of the film Top Gun Maverick is they have to take out this underground bunker that's purifying uranium.
  • Okay.
  • There's only one reason to do that, because you're going to make a bomb with it.
  • Right.
  • There's no other reason to have purified fissionable uranium.
  • Okay.
  • So what is more powerful, fission or fusion?
  • All right.
  • It turns out a fusion bomb, which is what the sun does, can become way more.
  • You can make bombs of different sizes.
  • But sky's the limit, practically, with a fusion bomb, starting with hydrogen.
  • And hydrogen goes to healing, but you need
  • It has to be small enough, and again, it has to be able to be self driven once you start it.
  • Okay?
  • So the bombs that were dropped over Hiroshima and Nagasaki were ten, twenty ish kilotons of TNT.
  • Fusion bombs, which came later, those were not perfected until like the late forties, early fifties, when we were working on them and finally tested them.
  • Those are capable of megatons of power.
  • So instead of kilotons, you have megatons, a thousand times more powerful.
  • Damn.
  • Because apparently one bomb leveling a city was not powerful enough in the Cold War.
  • And so that's why they say the XXth century was the century of the physicists, because the Cold War defined geopolitics, and the Cold War came about because of the handiwork of physicists, combined with engineers, to actually make the bomb.
  • And so, yeah, there's a nuclear bomb will not only ignite
  • The pulse of energy is enough to sort of incinerate whatever is in a sight line to it.
  • But then there's the blast wave that'll completely level anything that happens after that.
  • Because the pulse happens at the speed of light.
  • The blast wave moves at the speed of sound, which is slower.
  • So if you're not incinerated, the blast wave will take you out, basically.
  • Wow.
  • And one of the concerns about, you want to talk about climate change, is if
  • If you target a city, it's one thing if you target forests, well then you incinerate the forests and that'll put soot into the air, wreaking havoc with our climate.
  • If you do it over cities, let's take LA for example, where there's all these freeways, if the freeways are made of asphalt,
  • It's possible for the asphalt to catch fire.
  • Yes.
  • And you literally rain fire from the explosion.
  • Correct.
  • And that, you want to talk about further disrupting the climate.
  • I know if you were where the blast wave was, you're not really concerned about the climate.
  • You're concerned about whether you were vaporized or not.
  • But the rest of the world would then feel this.
  • So this is, I mean, it's an extraordinary,
  • power that we wield and We rapidly realized we needed some way to regulate it so we had these test ban treaties and this sort of thing right and I
  • And now we have Kim Jong un.
  • So what could go wrong?
  • What could possibly go wrong?
  • Oh, and by the way, early in this, they did a calculation.
  • They said, if we set off a chain reaction in this bomb, will that chain reaction continue into our atmosphere?
  • Oh, right.
  • Because the water molecules in the atmosphere, there's hydrogen in the water molecules.
  • There's hydrogen in the oceans, OK?
  • Would this start a chain reaction and completely incinerate our atmosphere and our oceans?
  • So you can do a calculation and show that it's not likely.
  • OK.
  • Well, that's comforting.
  • Well, the problem in physics, every calculation has a statistic, especially in quantum physics.
  • There's a statistical probability that could be vanishingly small.
  • But if you're honest, you'd report that even though it's vanishingly small.
  • No, part of the problem is, in order to have this runaway fusion, you need the concentration of materials for that to happen.
  • And you don't get that in the ocean or the oceans, right?
  • That's part of the problem.
  • Oh, man, I gotta tell you, I haven't seen the movie, but I don't want to now.
  • No.
  • I'm just saying.
  • I have not seen Oppenheimer, but I do not want to now.
  • This is frightening.
  • Yeah, and it's all the energy that comes out of E equals MC squared.
  • Yeah.
  • And Einstein himself, he sent a letter to Roosevelt saying, I think the Nazis are working on this.
  • We should too, OK?
  • Nice.
  • Then we start the Manhattan Project.
  • But then he realized maybe this is not a good thing.
  • Once we learned that the Nazis were not really close to it, that was an occasion to say, OK, we're done here.
  • Let's resort to conventional weapons.
  • And we didn't.
  • We pursued it.
  • The frontier of physics.
  • Oh well.
  • Welcome to human civilization.
  • Hey, I'm going to sleep really well tonight.
  • Unbelievable.
  • All right, Chuck.
  • Well, you started it with your question here.
  • This is true.
  • I asked for this, so I deserve every bit of it.
  • All right.
  • That's all the time we have.
  • That's been another StarTalk Explainer.
  • Always good to have you, Chuck.
  • Always a pleasure.
  • All right.
  • Until next time, Neil deGrasse Tyson here.
  • Keep looking up.