In which type or types of radioactive decay does the mass number of the parent nucleus not change?

Question

Quizplus · Accepted Answer

In both beta decay and electron capture, the number of protons in the nucleus changes, but the mass number remains the same. This is because beta decay involves the conversion of a neutron into a proton and an electron, while electron capture involves the capture of an electron by a proton to form a neutron. Both processes result in a change in atomic number (i.e. the number of protons), but the total number of nucleons (i.e. protons plus neutrons) remains constant. Alpha decay, on the other hand, involves the emission of a helium nucleus (i.e. an alpha particle), which has a mass number of 4 and an atomic number of 2, so both the mass number and atomic number of the parent nucleus decrease.

In Which Type or Types of Radioactive Decay Does the Mass