Question

Why does some elements have different valencies? (like in the case of iron).please help...

Answer 1

Some elements show the Variable Valencybecause of the different electronic configuration. An aton an element cansometimes lose more electrons than arepresent in its valance shell i.e, loss from the penultimates shell and hence exhibit more than 1 or variable valency.

Answer 2

The combining capacity of an atom  in case of metals exhibiting variable valence we represent the power valency by adding the suffix ous to the name of metal to represent the higher valency the suffix ic is attached to name of the metal