Answer:
C6H6(g) → 6CH(g)
Step-by-step explanation:
Benzene is formed by a ring of 6 carbons, alternating single and double bonds between them, and each carbon is bonded to one hydrogen. When the carbon-carbon bonds are broken, only the carbon-hydrogen bonds remain, so the reaction must be:
C6H6(g) → 6CH(g)
CH is an unstable radical and will react with the other radicals to be more stable.