Question

The initial concentration of a radioactive substance is No and its half life is 12 hours. What will be its concentration after 36 hours?​

Answer 1

Answer:

The concentration after 36 hours will be No/8.

Explanation:

In a radioactive decay process, when half of the sample undergoes in to radioactive decay process and changes into another substance that time period is know as nuclear half life of the sample.

Radioactive decay of the sample can be expressed mathematically as

N = No {1/2}^t/1/2t

Here N is initial concentration and No is the concentration after time t.

N = No{1/2} ^ 36/12/1 = N0 x {1/2} ^3

   = No/8

Thus the concentration after 36 hours will be No/8.