Answer:
2Al+3Fe ------- Al2O3+3Fe
this is answer no 2
N2+3H2------- 2NH3
this is answer no 3
I think helps
Best of luck
D:
When electrons are gained, the charge of the atom decreases.
When you are given an atom with a charge, the oxidation of that atom is the charge. So by going from a Cr^3+ (Oxidation Number = 3) to a Cr^2+ (Oxidation Number = 2), the Oxidation Number thus decreases.
