Question

The number of which subatomic particle designates the atomic number of an element? select one:

Answer 1

The atomic number is determined by the number of protons in the atom.

Neutrons can vary the mass of atoms of the same element; atoms of the same element with the different atomic masses are called isotopes.

Electrons do not contribute a meaningful amount of mass to an atom, and only vary the charge of the atom. A charge atom is an ion.

Answer 2

the number of protons always equals the atomic number of an element.