Half-Life

Front

What is half-life?

Back

The time required for half of the radioactive atoms in a sample to decay.

Front

What is the half-life of iodine-131?

Back

8 days.

Front

If one-fourth of the carbon-14 is remaining, how many half-lives have passed?

Back

2 half-lives.

Front

Why do some elements have half-lives?

Back

They radioactively decay.

Front

What percentage of the parent isotope remains after 2 half-lives?

Back

25%.

Front

After the third half-life, how much of the sample is left?

Back

1/8 of the original sample.

Front

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

Back

Remaining quantity = Initial quantity * (1/2)^n.

Front

What is radioactive decay?

Back

The process by which an unstable atomic nucleus loses energy by radiation.

Front

What is a parent isotope?

Back

The original radioactive isotope that undergoes decay.

Front

What is a daughter isotope?

Back

The product of the decay of a parent isotope.