What is the only nonmetal on left side of the periodic table?
This is an interesting question, because although there is a non-metal on the left side, Hydrogen, it can also act as a cation (something a metal would normally be).
Hydrogen is a very special element. Not only does it have 0 neutrons (not including isotopes), but that one proton results in having one more electron OR one less electron.
Thus, Hydrogen can act as a cation, like in acids, or an anion, like in molecular compounds.
Hope this helps :)