Question

A nucleus ${}_Z^{A}X$ going through a ${\beta }^{+}$ decay will end up taking what configuration?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

A proton in the ${}_Z^{A}X$ nucleus absorbs an electron (equivalently, releasing a positron) to become a neutron, releasing a neutrino in the process. Thus the atomic number Z is bound to decrease by 1, but the number of nucleons being constant, the mass number A will stay the same. Thus the complete decay would be:
$\begin{array}{c}{}_Z^{A}X{\to }_{Z-1}^{A}Y+e^{+}+v\end{array}.$