A triple bond consists of 1 sigma bond and 2 pi bonds.

C2H4 has a double bond between the carbon atoms, indicating sp2 hybridization.

Bond order = (Number of bonding electrons - Number of antibonding electrons) / 2 = (5 - 5) / 2 = 0.

The bond angle in a tetrahedral geometry is approximately 109.5 degrees.

PCl5 has 5 bonding pairs and no lone pairs, resulting in a trigonal bipyramidal geometry.

A pi bond is formed by the lateral overlap of two p orbitals.