Question

An element $E$ combines with oxygen to form an oxide $E_{2}O$ which is good conductor of electricity. Give the following information:

1. How many electron will be present in the valence shell of element $E$?
2. Write the formula of the compound formed when the element $E$ combines with chlorine.

Answer 1

The element $E$ combines with oxygen to form an oxide $E_{2}O$ that means element $E$ is metallic in nature with the valency of 1. For example, when Potassium ($K$) metal combines with Oxygen ($O_2$), it produces Potassium oxide ($K_{2}O$). The chemical reaction is as follows.

$\underset{potassium}{4K\left(s\right)}+\underset{oxygen}{O_2\left(g\right)}\to \underset{potassiumoxide}{2K_{2}O\left(s\right)}$

Therefore the element $E$ is Potassium ($K$).

1. The valency of the element $E$ is one, as seen by the oxide's composition $E_{2}O$. This indicates that the valence shell of the element $E$ contains only one electron.
2. Chlorine ($Cl$) is monovalent, as we all know. The formula of the compound formed when the element $E$ combines with chlorine is Potassium chloride ($KCl$).