Which of the following molecular orbital has two nodal planes perpendicular to each other?

Options

A. `sigma_(2s)`
B. `pi_(2px)`
C. `pi_(2py)^(**)`
D. `sigma_(2pz)^(**)`

Answer

To solve the question of which molecular orbital has two nodal planes perpendicular to each other, we will analyze each option provided and determine the characteristics of the molecular orbitals mentioned.

### Step-by-Step Solution:

1. **Understanding Nodal Planes**:
- Nodal planes are regions in a molecular orbital where the probability of finding an electron is zero. This means that the electron density in these regions is absent.

2. **Analyzing Option 1: Sigma 2s Bonding Orbital**:
- The sigma 2s bonding orbital is formed by the constructive overlap of two 2s orbitals. The 2s orbital is spherical in shape.
- Since the bonding orbital does not have any regions with zero electron density, it does not contain any nodal planes.
- **Conclusion**: No nodal planes in sigma 2s.

3. **Analyzing Option 2: Pi 2px Bonding Orbital**:
- The pi 2px bonding molecular orbital is formed by the constructive overlap of two 2px orbitals. It has a nodal plane that lies along the inter-nuclear axis.
- There is only one nodal plane present in this molecular orbital.
- **Conclusion**: Contains one nodal plane.

4. **Analyzing Option 3: Pi Star 2py Anti-bonding Orbital**:
- The pi star 2py molecular orbital is formed by the destructive overlap of two 2py orbitals. This orbital has regions of positive and negative electron density.
- In this case, there are two nodal planes: one in the x-z plane and one in the y-z plane, which are perpendicular to each other.
- **Conclusion**: Contains two nodal planes that are perpendicular to each other.

5. **Analyzing Option 4: Sigma Star 2pz Anti-bonding Orbital**:
- The sigma star 2pz molecular orbital is formed by the destructive overlap of two 2pz orbitals. This orbital has regions of zero electron density.
- However, it contains three nodal planes, which are all parallel to each other.
- **Conclusion**: Contains three nodal planes, all parallel.

6. **Final Answer**:
- Based on the analysis, the correct answer is **Option 3: Pi Star 2py**, which has two nodal planes that are perpendicular to each other.