Which of the following compounds is aromatic?

• A. Cyclohexane ($C_6{H}_{12}$)
• B. 1,3,5-Hexatriene ($C_6{H}_8$)
• C. Cyclobutadiene ($C_4{H}_4$)
• D. Benzene ($C_6{H}_6$)

Answer: (D)

Verified step by step guidance

1. Recall the criteria for aromaticity: a compound must be cyclic, planar, fully conjugated (p orbitals at every atom in the ring), and follow Hückel's rule, which states it must have \$4n + 2\( π electrons, where \)n$ is a non-negative integer (0, 1, 2, ...).
2. Analyze each compound to check if it meets these criteria. For example, cyclohexane (\(C_6H_{12}\)) is cyclic but saturated (no π bonds), so it is not aromatic.
3. Look at 1,3,5-hexatriene (\(C_6H_8\)), which has conjugated double bonds but is not cyclic, so it cannot be aromatic.
4. Examine cyclobutadiene (\(C_4H_4\)), which is cyclic and conjugated but has 4 π electrons, which fits \$4n\( (with \)n=1\(), not \)4n+2$, so it is antiaromatic rather than aromatic.
5. Finally, consider benzene (\(C_6H_6\)), which is cyclic, planar, fully conjugated with 6 π electrons. Since 6 fits Hückel's rule (\$4n + 2\( with \)n=1$), benzene is aromatic.