Half-life Exit Ticket

Front

What is half-life?

Back

Half-life is the time required for half of the radioactive atoms in a sample to decay.

Front

If a substance has a half-life of 8 days, how much of a 10 mg sample remains after 8 days?

Back

5 mg

Front

How much of a 10 mg sample remains after 16 days if the half-life is 8 days?

Back

2.5 mg

Front

What is the formula to calculate the remaining amount of a substance after a certain number of half-lives?

Back

Remaining amount = Initial amount × (1/2)^(number of half-lives)

Front

If the half-life of a substance is 2 minutes, how much of an 80 g sample remains after 6 minutes?

Back

10 g

Front

What is the half-life of iodine-131?

Back

8 days

Front

How many half-lives are needed for a 10 g sample to reduce to 1.25 g if the half-life is 70 years?

Back

3 half-lives

Front

If a sample of 100 g of Zn-71 has a half-life of 2.4 minutes, how much remains after 4.8 minutes?

Back

25 g

Front

What happens to the amount of a radioactive substance over time?

Back

It decreases exponentially as it undergoes decay.

Front

If a substance has a half-life of 5 years, how much of a 40 g sample remains after 15 years?

Back

5 g