Question

Name two elements with variable valency.

Answer 1

Valency: It is the combining capacity of an element

Variable valency:

• There are Some elements that have different capacities to combine with different elements. It depends on the nature of the reaction of that element.
• This property of having different capacities to combine with different elements is known as variable valency.
• Example: Iron (Fe) and copper (Cu) are the metal elements that can form two types of oxides of it.
• In the formation of ferrous oxide (FeO), the valency of iron (Fe) is +2 whereas, in ferric oxide (Fe₂O₃), the valency of iron (Fe) is +3.
• In the formation of cuprous oxide (Cu₂O), the valency of copper (Cu) is +1 whereas, in Cupric oxide (CuO), the valency of copper (Cu) is +2.