How many pi electrons are in benzene?

Benzene contains 6 pi (π) electrons.

Benzene's structure, a cyclic molecule with alternating single and double bonds, leads to a delocalized π electron system above and below the plane of the ring. This delocalization is what gives benzene its unique stability and properties.

Here's a breakdown:

• Benzene's formula is C₆H₆.
• Each carbon atom is sp² hybridized.
• The sp² hybridization leaves one unhybridized p orbital on each carbon atom. These p orbitals are perpendicular to the plane of the ring.
• These six p orbitals overlap sideways to form a continuous π system.
• Each double bond contributes two π electrons. Since benzene can be represented with three double bonds, it has 3 x 2 = 6 π electrons.
• According to Hückel's rule, aromatic compounds have (4n+2) π electrons, where n is an integer. For benzene, n=1, so it follows Hückel's rule (4(1)+2 = 6).

This delocalization of the 6 π electrons is crucial for benzene's stability and resistance to addition reactions.