Which molecule is planar

Options

A. `CH_4`
B. `C_2H_6`
C. `NH_3`
D. `C_6H_6`

Explanation

To determine which molecule is planar, we need to analyze the hybridization of the atoms involved in the molecules in question. Here’s a step-by-step solution:

### Step 1: Understand Hybridization
Hybridization refers to the mixing of atomic orbitals to form new hybrid orbitals. The type of hybridization can influence the geometry of the molecule.

**Hint:** Remember that sp3 hybridization results in a tetrahedral shape, while sp2 hybridization leads to a trigonal planar shape.

### Step 2: Identify the Hybridization of Each Molecule
1. **CH4 (Methane)**:
- Carbon in CH4 is surrounded by four hydrogen atoms, leading to sp3 hybridization.
- Geometry: Tetrahedral (not planar).

2. **C2H6 (Ethane)**:
- Each carbon in ethane forms four single bonds (with hydrogen), resulting in sp3 hybridization.
- Geometry: Tetrahedral (not planar).

3. **NH3 (Ammonia)**:
- Nitrogen forms three sigma bonds with hydrogen and has one lone pair, leading to sp3 hybridization.
- Geometry: Trigonal pyramidal (not planar).

4. **C6H6 (Benzene)**:
- Each carbon in benzene is bonded to one hydrogen and has a double bond with another carbon, leading to sp2 hybridization.
- Geometry: Planar (due to the presence of double bonds and resonance).

**Hint:** Look for double bonds or lone pairs that can affect the molecular geometry.

### Step 3: Conclusion
From the analysis, the only molecule that exhibits planar geometry is **C6H6 (Benzene)**, as it has sp2 hybridized carbon atoms.

**Final Answer:** The planar molecule is **C6H6 (Benzene)**.