The half-life period of a radio-active element `X` is same as the mean life time of another radio-active element `Y`. Initially they have the same number of atoms. Then:

Options

A. `X` will decay faster than `Y`
B. `Y` will decay faster then `X`
C. `X` and `Y` have same decay rate initially
D. `X` and `Y` decay at same rate always

Answer

B

Explanation

`( l n2)/(lambda_(x))=(1)/(lambda_(gamma))=lambda_(gamma)=1.4lambda_(x), lambda_(gamma)gtlambda_(X), Y` will decay fater than `X`