In a triple bond, how many each pi and sigma bonds are there?

In a triple bond, there are two pi bonds and one sigma bond. Together, these three bonding components give the bond a bond order of three.

The sigma bond forms through direct overlap along the line connecting the two atomic nuclei. The two pi bonds form through sideways overlap of pairs of parallel p orbitals. These pi bonds occupy mutually perpendicular planes around the bond axis, creating the characteristic structure of a typical triple bond.

Acetylene, or ethyne, is the standard example: its carbon atoms are connected by a C≡C bond, and each carbon is also bonded to one hydrogen atom. The carbon atoms are sp-hybridized, giving acetylene a straight-line geometry with bond angles of 180 degrees. Triple bonds are shorter and generally stronger than comparable double or single bonds, although the individual pi components are weaker than the sigma component. Rotation around a triple bond is also restricted because it would disrupt the pi bonding.