Question

Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay process are `tau = 1// lambda` and `t_(1//2) = 0.693//lambda`. Therefore are a number of radioactive elements in nature, their abundance is directly proportional to half life. The amount remaining after `n` half lives of radioactive elements can be calculated using the relation:
`N = N_(0) ((1)/(2))^(n)`
Half life of `.^(60)Co` is 5.3 years, the time taken for 99.9% decay will be
A. 0.53 years
B. 53 years
C. 530 years
D. 5300 years

Answer 1

Correct Answer - B
`t_(99.9%) = 10 t_(1//2)`
`10 xx 5.3 = 53` years