How much strontium-90 was present in the bone when the animal died 45 years ago. The half-life of 90Sr is 29 y

Question

You have a sample of bone collected from Nevada and you find that it contains strontium-90 and exhibits an activity of 2.5 Bq. How much strontium-90 was present in the bone when the animal died 45 years ago. The half-life of 90Sr is 29 years.

a 1.1 x 10^8

b 9.7 x 10^8

c 3.3 x 10^8

d 1.5 x 10^8

Answer 1

b9.7 x 10^8