VALENCY OF METALS
The Number of electrons lost by a metal is known as the valency of the metal.For example:
- 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.
- In the same way, an atom of magnesium loses 2 electrons so its valency is 2.
Mg Mg2+ + 2e-
- Aluminium atom loses 3 electrons so its valency is 3.
Al Al3+ + 3e-