Question

Write the name of two elements, which show variable valency.

Answer 1

• Valency: Valency is the combining capacity of an element with another atom to form a chemical bond; valance electrons are the electron present in an atom's outermost shell.
• Variable valency: Some elements show more than one type of valency which means for stability most of the elements lose their electrons from another shell also after the removal of valence electrons.
• Iron and copper are the elements that show variable valency.
• Valency: Iron - 1,2,3 Copper - 1,2,3
• Example : $$\begin{gathered} \mathrm{Fe},{\mathrm{Fe}}^{2+},{\mathrm{Fe}}^{3+} \\ \mathrm{Cu},{\mathrm{Cu}}^{2+},{\mathrm{Cu}}^{3+} \end{gathered}$$