Benzene is

Options

A. aliphatic
B. aromatic
C. alicyclic
D. heterocyclic

Explanation

**Step-by-Step Solution:**

1. **Identify the Chemical Formula of Benzene:**
- Benzene has the chemical formula C₆H₆. This indicates it consists of six carbon atoms and six hydrogen atoms.

2. **Understand the Structure of Benzene:**
- Benzene is structured as a six-membered ring. Each carbon atom in the ring is bonded to one hydrogen atom.

3. **Determine the Type of Compound:**
- We need to classify benzene among the given options: aliphatic, aromatic, alicyclic, or heterocyclic.

4. **Evaluate Aliphatic Compounds:**
- Aliphatic compounds are characterized by carbon and hydrogen atoms connected in straight or branched chains. Since benzene is a closed ring structure, it does not fall under this category.

5. **Evaluate Aromatic Compounds:**
- Aromatic compounds must be cyclic, follow Huckel's rule (4N + 2 π electrons), and exhibit resonance. Benzene meets all these criteria:
- It is cyclic.
- It has 6 π electrons (N=1 in Huckel's rule).
- It exhibits resonance, which contributes to its stability.
- Benzene undergoes substitution reactions rather than addition reactions.

6. **Evaluate Alicyclic Compounds:**
- Alicyclic compounds are cyclic compounds that can be saturated or unsaturated but do not necessarily have the resonance or substitution characteristics of aromatic compounds. Benzene does not fit this definition.

7. **Evaluate Heterocyclic Compounds:**
- Heterocyclic compounds contain atoms other than carbon in the ring structure. Benzene is composed solely of carbon and hydrogen, so it does not qualify as heterocyclic.

8. **Conclusion:**
- Based on the evaluations, benzene is classified as an aromatic compound. Therefore, the correct answer is option number 2: aromatic.

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