Multiple Covalent Bonds

The covalent bonds developed due to mutual sharing of more than one pairs of electrons are termed 'multiple covalent bonds'. These are:

Double covalent bond

The bond formed between two atoms due to the sharing of two electron-pairs is called a double covalent bond or simply a double bond. It is denoted by two small horizontal lines (=) drawn between the two atoms, e.g., O = O, O = C = O etc.

Triple covalent bond

Bond formed due to the sharing of three electron pairs is called a triple covalent bond or simply a triple bond. Three small horizontal lines between the two atoms denote a triple bond e.g., NN, and H-CC-H (acetylene).