Question

Based on the group valency of elements state the formula for the following also giving justification: Oxides of 1st group elements.

Answer 1

• The valency of group 1 elements is 1 as they have 1 electron in their outermost shell.
• The valency of oxygen is 2 as they have 6 electrons in their outermost shell and need only 2 more to achieve the octet state.
• Thus the compound will be formed in the following manner $$\begin{gathered} \left(\mathrm{X}\mathrm{O} \\ 12\right)={\mathrm{X}}_2\mathrm{O} \end{gathered}$$
• Here X is an element from group 1 and O is oxygen, and their valencies are written underneath them respectively.
• For example, an oxide of group 1 element is Sodium oxide$\left({\mathrm{Na}}_2\mathrm{O}\right)$.
• Two sodium atoms combine with 1 oxygen atom to form Sodium oxide with chemical formula $\left({\mathrm{Na}}_2\mathrm{O}\right)$