Question

Which of the following is the number of protons plus the number of neutrons?

Atomic charge
Mass number
Atomic number
Atomic isotope number

Answer 1

The number of protons plus the number of neutrons is the mass number.

The ionic charge depends on the number of electrons.

The atomic number is the number of protons.

Atoms can have different isotopic masses, but there is no such thing as atomic isotope number.