Question

Write a note on valency with respect to – 

1. Chlorine 

2. Oxygen

Answer 1

1. Valency with respect to Chlorine:

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

2. Valency with respect to oxygen:

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