A radioactive sample used in a hospital in Kingston, Jamaica has a half-life of 6 hours. If the initial activity is 800 Bq, what will be the activity after 18 hours?

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Question

A radioactive sample used in a hospital in Kingston, Jamaica has a half-life of 6 hours. If the initial activity is 800 Bq, what will be the activity after 18 hours?

Accepted Answer

100 Bq — Award 1 mark for correct calculation. 18 hours = 3 half-lives. After 1 half-life: 400 Bq. After 2 half-lives: 200 Bq. After 3 half-lives: 100 Bq. A is incorrect — this is only 1 half-life. B is incorrect — this is only 2 half-lives. D is incorrect — this would be 4 half-lives.

Answer

50 Bq

Answer

400 Bq

Answer

100 Bq

Answer

200 Bq

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