Covalent bonding occurs when atoms share electrons to achieve a more stable electron configuration. This type of bonding is prevalent in molecules made up of nonmetals.

When two atoms come close together, their outermost energy levels overlap, allowing for the sharing of electrons. The shared electrons are represented by a line between the atoms, called a covalent bond. The electrons in a covalent bond are attracted to the positively charged nuclei of both atoms, resulting in a strong bond.

One example of a molecule with a covalent bond is water (H₂O). In a water molecule, two hydrogen atoms share their electrons with an oxygen atom. This sharing of electrons forms two covalent bonds between the hydrogen and oxygen atoms, resulting in the stable and familiar water molecule.

Another example of covalent bonding is found in carbon dioxide (CO₂). In this molecule, one carbon atom shares its electrons with two oxygen atoms, forming two covalent bonds. This leads to the formation of a linear molecule with carbon in the center and two oxygen atoms on either side.

Covalent bonds can also differ in their strength and stability. Single covalent bonds involve the sharing of one pair of electrons, while double and triple bonds involve the sharing of multiple pairs of electrons. Double bonds consist of four shared electrons, represented by two lines, and triple bonds involve six shared electrons, represented by three lines.

In summary, covalent bonding occurs when atoms share electrons to achieve a more stable electron configuration. This type of bonding is commonly found in molecules of nonmetals. Examples of covalent compounds include water (H₂O) and carbon dioxide (CO₂). The strength and number of bonds can vary, with single covalent bonds involving one pair of shared electrons, double bonds involving two pairs, and triple bonds involving three pairs.