I sort of see what you are trying to say, but I think you're slightly misunderstanding what is going on. It is true that you are sharing electrons in a covalent

I sort of see what you are trying to say, but I think you're slightly misunderstanding what is going on. It is true that you are sharing electrons in a covalent bond, but it is not correct to therefore say that you need less electrons than in the atom state. A simple example: say you have to H atoms. Each has one electron. You put them together and form H2, which has two electrons combined. In both cases you need a total of two electrons, in order to have a neutral system. If you change that in any way, you will end up with highly reactive species (e.g. H+, H-, H2+, H2-). H+ is of course just an acid. What you are probably thinking of, is the fact that if you put NaOH, or HCl in water, you get Na+, OH-, etc., and these are more stable than their neutral counterparts. But this is because they are stabilised by (polar) water molecules. Outside of water (or some other stabilising solvent), Na+, OH-, H+ and Cl- are all very reactive species.