Definition of Sigma Bond
Sigma Bond is formed due to the overlapping of one pure or hybrid orbital, or two pure or two hybrid orbitals. These bonds are known to exist independently and they allow the free rotation around the axis of atoms. The strength of the sigma bond is very high. It is the first bond that is formed when the atoms interact with each other. After the formation of this bond, pi-bonds are formed.
When two atoms are bonded, only one sigma bond is formed. These bonds have cylindrical charge symmetry around its axis. The atoms which are bonded with each other through sigma bond are generally very reactive. Moreover, a sigma bond is used in determining the shape of the molecules.