Final answer:
Of the given compounds, only CH₂=CH-CH₂-CH₃ (1-butene) exhibits cis-trans isomerism, as it has different substituents on the carbons of the C=C double bond.
Step-by-step explanation:
Cis-Trans Isomerism in Compounds
Cis-trans isomerism, also known as geometric isomerism, occurs in alkenes and cyclic compounds where there is restricted rotation around the bond. This type of isomerism arises when two different groups are attached to each carbon of a C=C double bond or to two carbons in a ring structure. The isomers are differentiated based on whether the substituents are on the same side (cis) or on opposite sides (trans) of the bond or ring.
Let's consider the given compounds to determine if they exhibit cis-trans isomerism:
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- F₂C=CH₂: This compound has two fluorine atoms on one of its doubly bonded carbon atoms and fails to meet the criteria for cis-trans isomerism. Hence, it does not show cis-trans isomerism.
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- CH₂=CH-CH₂-CH₃: This compound, known as 1-butene, has different substituents on each of the doubly bonded carbons: a hydrogen and a methyl group on one, and an ethyl group on the other. It, therefore, meets the criteria and can have cis and trans isomers.
In summary, out of the two compounds listed, only compound 2 exhibits cis-trans isomerism.