Electron pair shared between two atoms results in the formation of a covalent bond. This shared pair is also called bonding pair of electron. If two atoms share one electron pair, bond is known as single covalent bond and is represented by one dash (-) If two atoms share two electron pairs, bond is known as double covalent bond and is represented by two dashed (=). If two atoms share three electron pairs, bond is known as triple covalent bond and is represented by three dashes (=).