For example if you combine sodium (Na) and chlorine (Cl) that is the same as +1 = -1 = 0 so you only need one of each. When we say one, it could mean one atom or one mole. So the formula for a combination of sodium and chlorine is Na + Cl - or often written with out the superscripts as NaCl.
Aug 13, 2020 · Since nitrogen has 5 valence electrons, the most that it can "lose" while forming bonds in a molecule is 5, so its highest possible oxidation number is \(+5\). Alternatively, it could gain up to 3 electrons, and so its lowest (most negative) possible oxidation number is \(-3\).