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 is the Half Life of this isotope if it is 3 days?

Back

3 days.

Front

If you have 100 grams of radioactive C-14, how many grams are left after 1 half life?

Back

50 grams.

Front

When nuclei decay, what is released?

Back

Energy.

Front

The half-life of strontium-90 is 25 years. How much will remain after 100 years if the initial amount is 4.0 g?

Back

0.25 g.

Front

What does a half-life indicate in radioactive decay?

Back

It indicates the time required for half of the radioactive nuclei in a sample to decay.

Front

If the half-life of an isotope is 10 years, how much of a 80 g sample remains after 20 years?

Back

20 g.

Front

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

Back

It decreases exponentially.

Front

What is the relationship between half-life and stability of an isotope?

Back

Isotopes with longer half-lives are generally more stable.

Front

How is half-life used in carbon dating?

Back

It helps determine the age of organic materials by measuring the remaining C-14.