Strontium-90 is used in machines that control the thickness of papaer during the manufacturing process. Stron?

Question

Strontium-90 has a half-life of 28 years. Determine how much time has elapsed if the following fraction of a strontium-90 sample remains.
a) 1/4

b) 1/8

c)1/32

Answer 1

These elasped times are all found from being integral powers of 1/2. So the time elasped will be the power of 1/2 times the half life. The powers are: for 1/4,2 for 1/8,3 and for 32, 5.