Valency of metals

The Number of electrons lost by a metal is known as the valency of the metal. For example: 

1. One atom of sodium loses 1 electron to form a positive sodium ion (Na⁺), so sodium is a metal

Na      →      Na⁺      +      e^–

Here because an atom of sodium loses 1 electron so the valency of sodium metal is 1.

2. In the same way, an atom of magnesium loses 2 electrons so its valency is 2.

Mg      →      Mg²⁺      +      2e^–

3. Aluminium atom loses 3 electrons so its valency is 3.

Al      →      Al³⁺      +      3e^–

Test your understanding and answer these questions:

1. What do you understand by valency? give examples.