If a radioactive sample contained 1600 billion nuclei and its half life was 57 years, after how many years would there be 400 billion nuclei remaining?

Choose 1 answer

57

114

171

400

800

1200

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What is activity measured in?

Choose 1 answer

Be

Bq

g

g/s

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What is the best definition of 'count rate'?

Choose 1 answer

how much radiation there is

the time taken for half the nuclei to decay

the rate at which a source of unstable nuclei decays

the number of decays recorded each second by a detector

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Fill in the blanks.

Select the missing words in the text.

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Answer incorrect

Look at the slide below to work out the answer.