(a) Explain the terms 'valency' and 'variable valency'.
(b) How are the elements with variable valency named ? Explain with an example.
a) In the orbits, electrons exist around an atomic nucleus.
The distance of the electrons from the nucleus depends on the number of orbits. The higher the orbit number, the more the distance.
Atoms try to achieve a stable condition like the nobler gases or the inert elements in the outermost by orbit accepting electrons.
It is called the atom’s vallency.
The capacity of few elements vary while combining with other elements based on the nature of the reaction. This is called variable valency.
b) Fe 3+ is Ferrate
Fe 2+ is Ferrous
Valency is defined as the combining capacity of an element. For example, the valency of Hydrogen is 1 as it has one electron in its outermost shell and requires one electron to become stable.
Some elements differ in their capacity to combine with other elements depending on the nature of the reaction; this property is called variable valency. For example, Iron (Fe) can have a valency of both 4 and 3.