In Which of the Following Decays Does the Atomic Mass $\alpha$

Multiple Choice

In which of the following decays does the atomic mass number of the daughter nucleus differ from that of the parent nucleus?

A) $\alpha$
B) $\beta ^ { + }$
C) $\beta ^ { - }$
D) $\gamma$
E) Answers (a) ,(b) ,and (c) are correct.