Which of the following `MO's have two nodal plane ? .

Options

A. `sigma2p_(z)`
B. `pi^(**)2p_(x)`
C. `pi^(**)2p_(y)`
D. `sigma^(**)2p_(z)`

Explanation

To determine which molecular orbitals (MOs) have two nodal planes, we need to understand the concept of nodal planes in molecular orbital theory. A nodal plane is a region in a molecular orbital where the probability of finding an electron is zero.

### Step-by-Step Solution:

1. **Understanding Nodal Planes**:
- A nodal plane is defined as a plane where the electron probability density is zero. In molecular orbitals, the number of nodal planes is related to the shape and type of the orbital.

2. **Identifying Molecular Orbitals**:
- We need to analyze the given molecular orbitals. The common types of molecular orbitals are σ (sigma), π (pi), and their corresponding antibonding orbitals (σ* and π*).

3. **Analyzing π and π* Orbitals**:
- For π (pi) molecular orbitals, which result from the lateral overlap of p-orbitals (e.g., p_x and p_y), we can observe that:
- The bonding π orbital has one nodal plane.
- The antibonding π* orbital has two nodal planes.

4. **Conclusion**:
- Therefore, the π* molecular orbital (specifically the antibonding π orbital) will have two nodal planes. This is because the antibonding nature introduces additional nodes compared to the bonding orbital.

5. **Final Answer**:
- The molecular orbital that has two nodal planes is the π* (pi star) orbital.