When a nucleus emits a beta particle, its atomic number
A) changes, but its mass number remains constant.
B) remains constant, and so does its mass number.
C) remains constant, but its mass number changes.
D) changes, and so does its mass number.
E) none of these

Question

Quizplus · Accepted Answer

When a nucleus emits a beta particle (either an electron or a positron), its atomic number changes because the number of protons changes. However, its mass number remains constant because the total number of protons and neutrons (which make up the mass number) does not change.

When a Nucleus Emits a Beta Particle, Its Atomic Number