Explanations:

The given compound is benzene which has the molecular formula C6H6. Benzene is a cyclic hydrocarbon with a ring of six carbon atoms. Each carbon atom is bonded to two other carbon atoms and one hydrogen atom. The carbon-carbon bonds in benzene are alternating single and double bonds, which gives the molecule its aromatic性質. There are three double bonds in benzene, and each double bond contains one pi bond. Therefore, there are a total of 3 pi bonds in the molecule.