Identify the substance oxidized, the substance reduced, and, if any, spectator ions.

4Al(s) + 3O2 → 2Al203 (s)
Oxidation:
Reduction:
Spectator Ions:

Oxidation is the loss of electrons. Reduction is the gain of electrons.

Al is zero oxidation state on the left to 3+ on the right. Is that a loss or gain of electrons?
O is zero oxidation state on the left to 2- on the right. Is that a loss or gain of electrons?
I don't see any spectator ions.