What is the term for the number of protons in an atom?

Atomic identity refers to the characteristic that distinguishes one element from another, primarily based on its atomic number. While the atomic number contributes to the identity of an element, it is not a standard term used to specifically denote the count of protons. Therefore, "atomic identity" is a broader concept rather than the precise term sought in this question.

Atomic mass measures the mass of an atom, typically expressed in atomic mass units (amu). It accounts for both protons and neutrons in the nucleus and is influenced by the isotope of the element. Consequently, atomic mass is not synonymous with the number of protons, as it includes neutrons and varies among isotopes of the same element.

Atomic weight is a weighted average of the masses of an element's isotopes, taking into account their relative abundances. Like atomic mass, it includes contributions from both protons and neutrons and is not directly related to the number of protons alone. Thus, atomic weight cannot accurately describe the specific quantity of protons in an atom.