For each candidate decay below

PHYSICS · Subjective · A Level · Physics · Particles and radiation · Particles and radiation

Problem

For each candidate decay below, decide whether it is allowed. Write the letter(s) of all allowed decays. A.

^{19}_{9}\text{F}\rightarrow\,^{19}_{10}\text{Ne}+e^-

^{23}_{11}\text{Na}\rightarrow\,^{23}_{10}\text{Ne}+e^++\nu_e

^{3}_{1}\text{H}\rightarrow\,^{3}_{2}\text{He}+e^-+\bar{\nu}_e