Which of the following compounds is aromatic?

• A. Cyclohexene
• B. Benzene
• C. Cyclooctatetraene
• D. Cyclobutadiene

Answer: (B)

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. First, determine if the compound is cyclic and planar, and if it has a continuous overlap of p orbitals (fully conjugated).
3. Count the number of π electrons in the ring for each compound. Remember that each double bond contributes 2 π electrons, and lone pairs or charges can also contribute if present.
4. Apply Hückel's rule by plugging the number of π electrons into the formula \$4n + 2\( to see if it fits for some integer \)n\(. If it does, the compound is aromatic; if it has \)4n$ π electrons, it is antiaromatic if planar and conjugated, or non-aromatic if non-planar or not fully conjugated.
5. Based on these analyses, identify which compound satisfies all aromaticity conditions. For example, benzene has 6 π electrons, is planar, cyclic, and fully conjugated, fitting Hückel's rule with \(n=1\), making it aromatic.