The half-life period of a radioactive element 'X' is same as the mean life of another radioactive element Y. Initially both of them have the same no. 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.

Choose the correct answer from the options given below:

C Only

Decay Constant $ \lambda = \frac{1}{t_{mean}} = \frac{0.693}{t_{half}}$

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 Y will decay at a faster rate than X.