What happens to the atomic number (Z) and the mass number (A) when a nucleus emits an alpha particle?
A) Z increases by 1; A is unchanged.
B) Z is unchanged; A is unchanged.
C) Z decreases by 2; A decreases by 4.
D) Z decreases by 1; A is unchanged.

Question

Quizplus · Accepted Answer

When a nucleus emits an alpha particle (which consists of 2 protons and 2 neutrons), its atomic number (Z) decreases by 2 (due to the loss of 2 protons), and its mass number (A) decreases by 4 (due to the loss of 2 protons and 2 neutrons).

What Happens to the Atomic Number (Z) and the Mass