"Benzene" is a differently bonded six carbon ring. Each carbon uses three of its valence elections to bond with its neighbors (2 carbons + 1 hydrogen). The 4th "pi" electron is left standing perpendicular to the ring. This gives the ring C--C--C--C--C--C-- bonds.
Carbon atoms then pair to link their pi electrons into "pi bonds" above and below the ring. The ring then has "conjugated" bonding of C=C--C=C--C=C- or C--C=C--C=C-C= (depending how the carbons pair).
But the alternate pairings are equally likely. And the ring thus rapidly "resonates" between both pairings. To step through this sequence of building Benzene’s bonds, repeatedly click this button:
