Covalent Bonds

Covalent bond is one of the main types of chemical bonds. The simplest covalent bond is within a hydrogen molecule (H₂).

Covalent bonds of atoms in hydrogen molecules

What is a covalent bond?

Each hydrogen atom has a single electron in a 1s orbital. It is very unlikely that one hydrogen atom will lose an electron and the other atom gain an electron to produce ions. Instead, each atom donates its electron to form a shared pair of electrons in a molecular orbital between the two hydrogen atoms.

This shared set up is called a covalent bond and each hydrogen atom has a share of two electrons. Covelent bonds are represented by the simplified chemical diagrams below.

The small crosses represent valency electrons and the single stroke represents a covalent bond. Below are other examples of covalent bonds. The examples below are water covalent bonds and methane covalent bonds.