Covalent Bonds

Covalent Bonds are chemical bonds formed by the sharing of a pair of electrons between atoms. The nuclei of two different atoms are attracting the same electrons. Therefore, unlike ionic bonds where an electron is moved from one atom to another the electrons are shared.

The Octet Rule is a tendency of atoms in molecules to have eight electrons in their valence shells. (Two for hydrogen atoms.) The octet rule is a general rule, but is not followed by all molecules.

Multiple Bonds are sometimes found in molecules so that the molecules satisfy the octet rule. A single bond (which was discussed earlier) is when a single pair of electrons is shared between the two atoms. A double bond is when two pairs of electrons are shared between two atoms. A triple bond is when three pairs of electrons are shared between two atoms. (Notice a trend?) Double and triple bonds mostly occur when the elements Carbon(C), Nitrogen(N), Oxygen(O) and Sulfur(S) are involved. An example of a molecule with double bonds is Carbon Dioxide (CO₂). Notice that each element ends up with eight electrons around it.