Question

Write a note on valency with respect to –

1. Chlorine
2. Oxygen.

Answer 1

1. Valency with respect to Chlorine:

1. Since the valency of chlorine is one, the number of chlorine atoms with which one atom of an element can combine is called valency.
2. In a sodium chloride (NaCl) molecule, one chlorine atom combines with one sodium atom. So, the valency of sodium is one.
3. But, in magnesium chloride (MgCl₂) valency of magnesium is two because it combines with two chlorine atoms.

2. Valency with respect to oxygen:

1. Valency can be defined as double the number of oxygen atoms with which one atom of an element can combine because the valency of oxygen is two.
2. For example, in magnesium oxide (MgO) valency of magnesium is two.