What kind of ionic charge is this

aluminum+oxygen

aluminum has 3 electrons to give but oxygen only needs 2, so where does that extra electron go and what kind of charge is it.explain

When an aluminum atom becomes an ion, it loses three electrons. When oxygen becomes an ion, each atom gains two electrons. Therefore in order for there to be no electrons "left over", two aluminum atoms react at the same time as three oxygens. (Actually, "in the ratio of" would be better wording.)

All of the above is indicated in the correct formula for aluminum oxide which is Al2O3 (both numbers should be subscripts).

There are more exotic combinations than Al2O3, like the neutral molecule AlO2, and the anion AlO2^-, which is sometimes called "aluminate" and has a -1 charge. The AlO3^3- anion is also called "aluminate".

There is no "giving" of electrons. The bonds in AlO2 or AlO2^- are covalent. In the AlO2^- anion there is an extra electron giving it the -1 charge. Aluminum is the central atom. There is a double bond to one oxygen and a single bond to the other oxygen.

[O-Al=O]^-

Molecular compound - the sharing of electrons ... since aluminium and oxygen is a non metal they have a molecular bond