Question

How are the elements having variable valency named? Give Two examples.

Answer 1

Variable Valency: Certain elements (metals and non-metals) exhibit more than one valency.
Among the metals, iron, copper, silver, etc. show variable valency.

For lower valency, a suffix -"ous", and for higher valency, a suffix-"ic" is attached at the end of the name of the metals.
Example:
For lower valency of iron metal Ferrous$\left[{\mathrm{Fe}}^{+2}\right]$ and for higher valency of iron metal Ferric $\left[{\mathrm{Fe}}^{+3}\right]$ is used.

For lower valency of copper metal Cuprous$\left[{\mathrm{Cu}}^{+1}\right]$ and for higher valency of copper metal Cupric $\left[{\mathrm{Cu}}^{+2}\right]$ is used.