Question

Calculate after 2.00 y, 1.986 g of a radioisotope

remains from a sample that had an original mass of
2.000 g.
a. calculate the half-life.
b. how much of the radioisotope remains after 10.00 y?

Answer 1

Answer!

After 2 years, 1.986 g of a radioisotope material remains from a sample of the original mass of 2g, what is the half-life of the sample? - Radioactive decay occurs according to the formula:

A = A0 * exp(-ln(2) * t/T1/2)

The Original activity or mass A0 will decay to be A after time t where T1/2 is the decay time or half-life. If you fill in the values for A, A0 and t (= 2 years) you will end up with a value of approximately 188 years for the half-life.