Question

Radioactive decay is a process that follows 1st order kinetics. The half-life decay for Cs-133 is 15,300 years, and for Cs-135 is 56 years.

The rate law is Rate = k(N) where N is the number of nuclei that decompose per unit of time. 

a) Calculate the rate constant for the decay of Cs-133 and Cs-135 

b) If one starts with 3.2 grams of pure Cs-135, how many nuclear disintegrations per-second occur initially? 

c) What mass of Cs-135 is left after 1.0 year, 10. years, and 100 years?

Answer 1

$4.5×10 ^{5}$

$1.7 ×10 ^{3}$