Question

How does a single covalent bond differ from a double covalent bond?

Answer 1

Covalent bonds are formed between two atoms or ions where the sharing of electrons takes place between the electron pairs. They are also called a molecular bond. The forces of attraction/repulsion between two atoms (when they share a bond pair/ electron pair) are known as a covalent bond.

Complete step by step answer:
The “covalence” word was termed by the scientist named Irving Langmuir, which states about the number of electron pairs shared by the neighbouring atoms. Generally, carbon exhibits such kinds of compounds. The pair of electrons that share the two atoms which are extended around the nuclei of atoms leading to create a molecule.

Depending upon the sharing of electrons they are classified into different categories:
(i) Single covalent bond
(ii) Double covalent bond
(iii) Triple covalent bond

(i) Single covalent bond: The electron pair shared between the two atoms, then such bonds are referred to be a single covalent bond. It is represented by a single dash $( - )$ . These kinds of bonds have less density and are weaker than double and triple bonds, even though the single covalent bonds.
For example, Methane( $C{H_4}$ ) is one example, where each hydrogen is sharing its electron with carbon and forming a single covalent bond. Where hydrogen and carbon are sharing one electron and completing their octet of methane ($C{H_4}$ ) molecule.

(ii) Double covalent bond: The two-electron pairs share between the two participating atoms and form a double covalent bond. It is represented as two dashes $( = )$ . The double covalent bonds are stronger than the single bond. This type is less stable.
For example, a Carbon dioxide ($C{O_2}$) molecule has two oxygen atoms with four valence electrons and one carbon atom with six valence electrons. Each oxygen atom shares its two electrons with carbon and forms a double bond.
$O = C = O$

Note: Triple covalent bond: The three electron pairs share between the two participating atoms and form a triple covalent bond. It is represented as two dashes $( \equiv )$. The triple covalent bonds are stronger than the single bond. This type is the least stable.
For example, Nitrogen (${N_2}$) molecule has two nitrogen atoms with five valence electrons each and forms three electron pairs for octet completion. Each nitrogen atom shares its two electrons and forms a triple bond.
$N \equiv N$