Question

What is the difference between Valency and Oxidation state?

Answer 1

Valency	Oxidation state
Valency is defined as the number of electrons present in the outermost shell of an atom.	Oxidation state is defined as the number of electrons share with another atom, or any loss and gain of electrons in an atom
2. It does not indicate any charge on the atom of a compound or molecule.	2. Oxidation state represent the charge on each atom and it may either be negative or positive.
3. Through valency the maximum number of bonds can be identified.	3. It does not show any type of linkage of bond.
4. For a pure element valency is the number of electrons present in the outermost shell.	4. For pure elements the oxidation state is always equal to 0.
5. Example: The atomic number of Sodium is 11, therefore it contains 1 electron in its outermost shell. This implies that the valency of Sodium is equal to 1.	5. Example: In Ammonia Nitrogen is having -3 oxidation state. The oxidation state can be calculated as follows: The oxidation state of Hydrogen is +1. Let us consider the oxidation state of Nitrogen to be x. Therefore, $$\begin{gathered} \mathrm{x}+3=0 \\ \mathrm{x}=-3 \end{gathered}$$