Half-Life

Front

What is Half-Life?

Back

The amount of time it takes for half the nuclei in a sample of the isotope to decay.

Front

What does a half-life of 3 days mean for an isotope?

Back

It means that after 3 days, half of the original amount of the isotope will have decayed.

Front

If a radioactive isotope has a half-life of 10 years, how much of a 20g sample will remain after 30 years?

Back

2.5g.

Front

How do you calculate the age of a rock sample based on its remaining radioactive element?

Back

If 25% of the radioactive element remains, it has gone through two half-lives.

Front

What is the half-life of copper-64?

Back

13 hours.

Front

If you start with 20g of copper-64, how much will remain after 26 hours?

Back

5g.

Front

What is the significance of half-life in radioactive decay?

Back

It helps determine how long it takes for a substance to reduce to half its original amount.

Front

How many half-lives are in 120 years if the half-life is 60 years?

Back

2 half-lives.

Front

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

Back

It decreases as the substance decays.

Front

If an isotope has a half-life of 5 days, how much of a 40g sample will remain after 15 days?

Back

5g.