In which type or types of radioactive decay does the mass number of the parent nucleus change?

Question

Quizplus · Accepted Answer

In beta decay and electron capture, a neutron in the nucleus is converted into a proton. This changes the atomic number, but the mass number remains the same. However, in beta decay, an electron is emitted from the nucleus, which means the mass number decreases by one. Therefore, in beta decay and electron capture, the mass number of the parent nucleus does change. In alpha decay, the mass number decreases by 4 and the atomic number decreases by 2, while in electron capture, the mass number remains the same.

In Which Type or Types of Radioactive Decay Does the Mass