Unstable nuclei attain stability through disintegration. The nuclear stability is related to neutron proton ratio `(n//p)`. For stable nuclei `n//p` ratio lies close to unity for elements with low atmoic numbers (20 or less) but it is more than 1 for nuclei having higher atomic numbers. Nuclei having `n//p` ratio either very high or low undergo nuclear transformation. When `n//p` ratio is higher than required for stability, the nuclei have the tendency to emit `beta`-rays. while when `n//p` ratio is lower than required for stability, the nuclei either emits `alpha`-particles or a positron or capture `K`-electron.

Options

A. `Cu_(68)`
B. `Cu^(59)`
C. `Cu^(68)`
D. `Cu^(67)`

Answer

D