a sample of a radioisotope had a mass of 100.0 grams. After exactly 24 days, 6.25 grams remained. The half life of the isotope is _________

Answer 1

ln(No/N) = kt
No = 100
N = 6.25
t = 24 days.
Solve for k, then substitute into the equation below.
k = 0.693/t_1/2 and solve for t_1/2