What are moles in chemistry?

A mole is a unit to describe an amount of something/specific substance. Typically standard for measuring a large quantity of small entities like atoms, molecules, or other particles.

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.