Question

What is variable valency? Give two examples of elements that show variable valencies.

Answer 1

Variable valency

• The combining capacity of an element is called valency and it is also defined as the number of hydrogen atoms that an element can displace or combine. The valency of hydrogen is 1.
• Some elements have more than one valency and they combine with atoms of other elements forming different compounds. These elements are said to have variable valency.

For example, iron combines with chlorine to form different compounds FeCl₂(Ferrous chloride) and FeCl₃(Ferric chloride)