The half-life period of a radioactive element x is same as the mean life time of another radioactive element y. Initially, both of them have the same number of atoms. Then,
(a) x and y have the same decay rate initially
(b) x and y decay at the same rate always
(c) y will decay at a faster rate than x
(d) x will decay at a faster rate than y

Options

A. X and Y have the same decay rate intially
B. X and Y decay at the same rate always
C. Y will decay at a faster rate than X
D. X will decay at a faster rate than Y

Answer

C

Explanation

As given `(T)_(x)=tau_(y) or 0.693/(lambda_(x))=1/(lambda_(y))`
`lambda_(x)=0.693lambda_(y) or lambda_(x)gtlambda_(x)`
As rate of decay =`lambdaN`
So Y decays at faster rate than X.