Illustrated Glossary of Organic Chemistry

Cyclohexene: A cyclic hydrocarbon of molecular formula C6H10, containing an internal, disubstituted alkene. 'Cyclohexene' usually refers to the more common Z (cis) alkene isomer; the E (transalkene isomer has significant ring strain and is therefore rarely encountered.

Molecular Structure of Cyclohexene

Lewis structure
Ball and spoke
Space-filling model