Multiple Bonds in Covalent Bonding
Covalent bonding is the sharing of one or more electron pairs. In many covalent bonding situations, multiple chemical bonds exist — more than one electron pair is shared. (In hydrogen and the other diatomic molecules, only one electron pair is shared.)
A nitrogen atom can fill its octet by sharing three electrons with another nitrogen atom, forming three covalent bonds, a so-called triple bond. The triple bond formation of nitrogen is shown in the following figure.
A triple bond isn’t quite three times as strong as a single bond, but it’s a very strong bond. In fact, the triple bond in nitrogen is one of the strongest bonds known. This strong bond is what makes nitrogen very stable and resistant to reaction with other chemicals.
It’s also why many explosive compounds (such as TNT and ammonium nitrate) contain nitrogen. When these compounds break apart in a chemical reaction, nitrogen gas is formed, and a large amount of energy is released.
Carbon dioxide is another example of a compound containing a multiple bond. Carbon can react with oxygen to form carbon dioxide. Carbon has four valence electrons, and oxygen has six. Carbon can share two of its valence electrons with each of the two oxygen atoms, forming two double bonds. These double bonds are shown in the following figure.