The oxidizing agent is the one that is reduced in the reaction. In this reaction, the charge of Cu falls from +2 to zero charge (neutral atom in the right side). Hence, CuO is the oxidizing agent. The reducing agent, the one being oxidized is carbon from zero charge to +4. The answer is CuO.
Psychical(you see the changes visible) and Chemical properties(they react and combine, you may see fizzing or bubbles).
2.91 is the amount of atoms
