6.3 Half-Life

Front

What is half-life?

Back

The time it takes for a radioactive substance to decay to half its original amount.

Front

If you start with 80 mg of a substance with a half-life of 4 days, how much will remain after 8 days?

Back

20 mg

Front

What happens to the amount of a radioactive substance after each half-life?

Back

It reduces to half of its previous amount.

Front

If a sample has a half-life of 10 years, how much of a 100g sample remains after 30 years?

Back

12.5g

Front

What is the formula to calculate the remaining amount after n half-lives?

Back

Remaining amount = Initial amount × (1/2)^n

Front

If you have 50g of a substance and it undergoes 3 half-lives, how much is left?

Back

6.25g

Front

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

Back

It helps determine the age of materials by measuring the remaining radioactive isotopes.

Front

How does the half-life of a substance affect its stability?

Back

Shorter half-lives indicate less stability and faster decay.

Front

If a radioactive isotope has a half-life of 5 days, how much of a 200g sample remains after 15 days?

Back

25g

Front

What is the relationship between half-life and radioactive decay?

Back

Half-life is a measure of the rate at which a radioactive isotope decays.