The half life of `._92U^(238)` against `alpha` decay is `1.5xx10^(17)s`. What is the activity of the sample of `._92U^(238)` having `2.5xx10^(21)` atom?

Explanation

Given, half-life, `T_(1//2) = 1.5 xx 10^(17)`s
Number of atoms, `N = 25 xx 10^(20)` atoms.
Activity of sample `R = lambda N`
`=(0.693 xx 25 xx 10^(20))/(1.5 xx 10^(17))`
=11,550 disintegration/s