The half-life of 32P is 14 days. You start with 10 picograms of 32P. How much is left after 28 days?

1 Answer
Dec 18, 2017

2.5 picograms

Explanation:

A half life is the length of time it takes for a sample to half in size.

The half life of 32P is given as 14 days and 10 picograms is your starting mass.

After one half life (14 days), you will have 5 picograms left (half of 10).

After two half lives (14 x 2 = 28 days), you will have 2.5 picograms left (half of 10, 5. Then half of 5, 2.5).