question_answer

Why are \[\alpha \]-particles emitted rather than protons or \[_{2}^{3}He\] nuclei?

Answer:

                This is because \[\alpha \]-particles have a high value of binding energy. With the emission of \[\alpha \] -particle, the binding per nucleus of the residual nucleus increases appreciably. In contrast, the emission of a proton or \[_{2}^{3}He\]nuclei may not be energetically favourable.