the atomic number of an atom is: a. the number of electrons a. the number of neutrons the number of protons…

Brief Explanations:

The atomic number of an atom is defined as the number of protons in its nucleus. In a neutral atom, the number of electrons equals the number of protons, but the atomic number specifically refers to protons. The number of neutrons is not part of the definition of the atomic number. The sum of protons and neutrons gives the mass - number.

Answer:

D. the number of protons