In terms of oxidizing and reducing properties, what are metal and non-metals?
Well metals tend to be reducing species...........
And non-metals tend to be oxidizing species.........
The Periodic Table may be understood in terms of the competition between nuclear charge,
On the other hand, when a valence shell is filled, and a new Period is begun, the NEW valence shell is farther removed from the nuclear core, and is not so tightly constrained by electrostatic interaction. And thus metals tend to be reducing species, that can readily (at least relatively) lose their electrons, and become oxidized.
Are you clear on what I have tried to argue?