Chemical bonding takes place due to acquire a state of minimum energy and maximum stability and to convert atoms into molecule to acquire stable configuration of the nearest noble gas. We divide atoms into three classes,
(1) Electropositive elements which give up one or more electrons easily. They have low ionisation potentials.
(2) Electronegative elements, which can gain electrons. They have higher value of electronegativity.
(3) Elements which have little tendency to lose or gain electrons.
Different types of bonds are formed from these types of atoms.