The atomic mass number of an atom is the total number of ___ in the atom.
A) electrons
B) neutrons
C) protons
D) protons and neutrons
E) protons, neutrons, and electrons

Question

Quizplus · Accepted Answer

The atomic mass number of an atom is the sum of the number of protons and neutrons in the nucleus of the atom. Electrons do not significantly contribute to the mass of the atom, so they are not included in the atomic mass number.

The Atomic Mass Number of an Atom Is the Total