Question

Name a few elements that exhibit covalency.

Answer 1

Covalency:

The number of electrons shared by an atom with another atom during the formation of covalent molecule to have eight electrons in its outermost shell (except Hydrogen) is known as covalency.

Example:

1. Consider a Hydrogen atom $\mathbf{\left(}\mathbf{H}\mathbf{\right)}$ having atomic number $1$. Thus, the number of electrons in a Hydrogen atom are $1$.
2. The electronic configuration of Hydrogen is $\left(1\right)$.
3. In order to form Hydrogen molecule $\mathbf{\left(}{\mathbf{H}}_{\mathbf{2}}\mathbf{\right)}$, two Hydrogen atoms share one electron each and attain stable nearest noble gas configuration.
4. As one Hydrogen atom shares one electron, the covalency of Hydrogen is $1$.

Elements that exhibit covalency:

Hydrogen $\mathbf{\left(}\mathbf{H}\mathbf{\right)}$, Chlorine $\mathbf{\left(}\mathbf{Cl}\mathbf{\right)}$, Oxygen $\mathbf{\left(}\mathbf{O}\mathbf{\right)}$, Carbon $\mathbf{\left(}\mathbf{C}\mathbf{\right)}$.