Question

Fe3- protons and electrons

Answer 1

Electron "cloud" of orbitals

Difference of number of electrons from number of protons defines the charge on an atom. For example, among atoms of iron, all with 26 protons, Fe2+ has 24 electrons and Fe3+ has 23 electrons, whereas elemental (uncharged) Fe has 26 electrons. the mass of an atom is outside the nucleus.