What does a cis-isomer look like?
cis/trans isomerism (also known as geometric isomerism) is a form of stereo isomerism describing the relative orientation of functional groups within a molecule. The terms cis and trans are from Latin, in which cis means "on the same side" and trans means "on the other side" or "across". Usually, for acyclic systems trans isomers are more stable than cis isomers. This is typically due to the increased unfavorable steric interaction of the substituents in the cis isomer. Therefore, trans isomers have a less exothermic heat of combustion, indicating higher thermochemical stability.trans-1,2-dichlorocyclohexanecis-1,2-dichlorocyclohexane