Find the decay rate of the substance having `4xx10^15` atoms. Half life of a radioactive substances in `alpha`-decay is `1.2xx10^7` is

Options

A. `4.6 xx 10^(12)` atoms / s
B. `2.3 xx 10^(11)` atoms / s
C. `4.6 xx 10^(10)` atoms / s
D. `2.3 xx 10^(8)` atoms / s

Answer

D

Explanation

`(dN)/(dt) = - lamda N rArr |(dN)/(dt)| = (0.693)/(T_(1//2)) N`
`rArr (0.693)/(1.2 xx 10^(7)) xx 4 xx 10^(15)= 2.3 xx 10^(8)` atom/sec