Question

Phosphourous-32 is a radioisotope with a half-life of 14.3 days. If you start with 4 g of

phosphorous-32, how many grams will remain after 57.2 days? How many half-lives will have
passed?

Answer 1

Radioactice decay

Known :

T = 14.3 days

Mo = 4 gr

t = 57.2 days

Solution :

M = Mo • (1/2)^(t/T)

M = (4 gr)(1/2)^(57.2/14.3)

M = 0.25 gr