GCSE Physics | Half Life

Question 1

A radioactive chemical has an activity of 10,000Bq. What is the activity of this chemical after 2 half-lives have passed?

Question 2

A scientist finds a piece of radioactive rock with an activity of 800Bq. What will be the activity of this rock after 5 half-lives have passed?

Question 3

The radioactive source used to sterilise medical equipment being manufactured in a factory has an activity of 200kBq (200,000Bq). Calculate the activity of this source 4 half-lives later.

Question 4

A radioactive sample in a laboratory has a half-life of 10 days. If the sample has an activity of 4800Bq when it is returned to the safe, what will be it’s activity when it is next used 40 days later?

Question 5

A scientist prepares a radioactive solution with a half-life of 36 hours. Using a GM tube, the scientist says the liquid has a count rate of 72kBq. What will be the activity of the solution (in Becquerels) if it is measured again in 108 hours?

Question 6

The activity of a radioactive material is 1728Bq. After 24 hours, the activity has fallen to 27Bq. Calculate the halflife of the radioactive material.

Question 7

A radioactive chemical is prepared in a laboratory. The chemical has an initial activity of 272kBq. The activity of the chemical is rechecked 3 hours later and found to be 17kBq. What is the half-life of the chemical?

Question 8

The activity of a radioactive material is 344Bq. Two days later, the activity of the same material has fallen to 43Bq. Calculate the half-life of the material.