Oxidation is de-electronation whereas reduction is electronation. Oxidants are the substances which oxidise others and reduced themselves. On the other hand reductants are the substances which reduce others and oxidised themselves. The oxidation number of an element in a compound decides its nature to act as oxidant or reductant. Oxidation-reduction occur simultaneously and the overal chemical change is called redox reaction. Redox reactions are of three types :
(i) Intermolecular erdox reactions, (ii) Auto-redox or disproportionation reaction, and (iii) Intramolecular redox reactions.
Oxidation number of `Y` in `YBa_(2)Cu_(3)O_(7)` is `+3`, then oxidation number of `Cu` is :
A. `+7//3`
B. `+5//3`
C. `+2`
D. `+1`
