What is the formula of cyclohexane? 

C₆H₁₂

The correct answer is option 3. C₆H₁₂

Cyclohexane is a cyclic hydrocarbon, meaning it has a ring of carbon atoms with hydrogen atoms attached.

The prefix "cyclo" indicates a ring structure.

"Hexane" implies six carbon atoms (hexa-) in the molecule.

Following the octet rule (where atoms aim for eight valence electrons in their outer shell), each carbon atom in cyclohexane bonds with two hydrogen atoms.

Therefore, the correct formula is C₆H₁₂.