Question

check the box under each molecule in the table below that is an isomer of this molecule: if there are no isomers, check the none of the above box under the table.

Explanation:

Step1: Determine the molecular formula of the given cyclo - hexane

Cyclo - hexane ($C_6H_{12}$) has 6 carbon atoms and 12 hydrogen atoms.

Step2: Analyze the first molecule

The first molecule is a pentene ($C_5H_{10}$), not an isomer of $C_6H_{12}$.

Step3: Analyze the second molecule

The second molecule is methyl - cyclobutane ($C_5H_{10}$), not an isomer of $C_6H_{12}$.

Step4: Analyze the third molecule

The third molecule is hex - 2 - ene ($C_6H_{12}$), it is an isomer of cyclo - hexane as it has the same molecular formula but different structure.

Step5: Analyze the fourth molecule

The fourth molecule is 3 - methyl - pent - 2 - ene ($C_6H_{12}$), it is an isomer of cyclo - hexane as it has the same molecular formula but different structure.

Answer:

Check the box under the third molecule (hex - 2 - ene) and the fourth molecule (3 - methyl - pent - 2 - ene)