Question

Find out the valency and covalency shown by the:

(c) Carbon atom.

Answer 1

Valency:

The combining capacity of the atom of an element with the atoms of other elements in order to acquire eight electrons in its outermost shell is known as valency.

Valency of Carbon $\mathbf{\left(}\mathbf{C}\mathbf{\right)}$:

1. Carbon atom $\mathbf{\left(}\mathbf{C}\mathbf{\right)}$ has atomic number $6$. Thus, the number of electrons in a Carbon atom are $6$.
2. The electronic configuration of Carbon is $(2,4)$.
3. In order to acquire eight electrons in the outermost shell, Carbon atom shares $4$ electrons with the other atoms.
4. This results in formation of $4$ bonds with other atoms.
5. Thus, the valency of Carbon is $4$.

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 is known as covalency.

Covalency of Carbon $\mathbf{\left(}\mathbf{C}\mathbf{\right)}$:

1. Carbon atom $\mathbf{\left(}\mathbf{C}\mathbf{\right)}$ has atomic number $6$. Thus, the number of electrons in a Carbon atom are $6$.
2. The electronic configuration of Carbon is $(2,4)$.
3. Carbon requires $4$ more electrons to attain a stable electronic configuration.
4. Thus, Carbon atom forms $4$ covalent bonds by mutually sharing $4$ electrons with four electrons of four other atoms.
5. Thus, Carbon is tetravalent.
6. Thus, the valency of Carbon is $4$.