Which of the following compounds would you expect to be aromatic?

• A. Cyclobutadiene ($C_4{H}_4$)
• B. Benzene ($C_6{H}_6$)
• C. Cyclooctatetraene ($C_8{H}_8$)
• D. Cyclohexene ($C_6{H}_{10}$)

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 determine if it meets these criteria. First, check if the compound is cyclic and planar with continuous overlap of p orbitals (fully conjugated).
3. Count the number of π electrons in the ring for each compound. For example, each double bond contributes 2 π electrons. Use this to find the total π electrons in the ring.
4. Apply Hückel's rule by plugging the total π electrons into the formula (4n + 2). If the number fits this formula for some integer n, the compound is aromatic.
5. Based on these steps, identify which compound(s) satisfy all aromaticity conditions, especially focusing on benzene, cyclobutadiene, cyclooctatetraene, and cyclohexene.