Srinivas Rao
Last Activity: 14 Years ago
Radio active decay follows first order kinetics.
So, rate of decay is given by Rate = k [N0 (1/2/)n] where k is decay constant. k =0.693/ t1/2 ; n is number of half-lives.
(i) Initially, n=0
So, Rate -1 = (0.693/ 1) N0 and Rate-2 = (0.693/ 2) N0
Or (Rate-1 / Rate-2 ) = 2
(ii) After 2 Hours
2 Hours is 2 half lives for for A and 1 Half life for B
Rate -1 = (0.693/ 1) N0 (1/2)2 and Rate-2 = (0.693/ 2) N0 (1/2)1
(Rate-1 / Rate-2 ) = 1
(iii) After 10 Hours
10 Hours is 10 half lives for for A and 5Half life for B
Rate -1 = (0.693/ 1) N0 (1/2)10 and Rate-2 = (0.693/ 2) N0 (1/2)5
(Rate-1 / Rate-2 ) = 0.0625