Masses of two isobars `._(29)Cu^(64)` and `._(30)Zn^(64)` are `63.9298 u` and `63.9292 u`, respectively. It can be concluded from these data that .

Options

A. both the isobars are stable
B. `.^(64)Zn` is radioactive, decaying to `.^(64)Cu` through `beta-` decay
C. `.^(64)Cu` is radioactive, decaying to `.^(64) Zn` through `beta`-decay
D. `.^(64)Cu` is radioactive, decaying to `.^(64)Zn` through `gamma`-decay

Answer

c

Explanation

Expected atomic mass of `Cu` must be less than that of zinc, but it is not so. So, it means `Cu` is radiactive and unstable and decays to `Zn` through `beta` -decay.