What's the difference between neutral and stable? As an example of H2. Here two H atoms combine and make an H2 molecule. Now two H atoms are neutral as they have the same number of protons and electrons. So the H2 molecule is neutral. on the other hand. Two H atoms combine through a covalent bond and complete their valence electrons shells. At this condition this molecule is stable. So what to call this H2 molecule neutral or stable?