Which of the following orbitals is not symmetrical about the Z-axis?

Options

A. `p_(z)`
B. `d_(z) 2`
C. `s`
D. `d_(xz)`

Answer

To determine which of the given orbitals is not symmetrical about the Z-axis, we will analyze each of the orbitals mentioned in the question step by step.

### Step 1: Understand the Orbitals
1. **Pz Orbital**: The Pz orbital is oriented along the Z-axis. It has a dumbbell shape with lobes extending in the positive and negative Z directions. This orbital is symmetrical about the Z-axis.

2. **S Orbital**: The S orbital is spherical in shape. It is symmetrical about all axes (X, Y, and Z). Therefore, it is symmetrical about the Z-axis.

3. **Dz² Orbital**: The Dz² orbital has a unique shape that consists of a lobular structure along the Z-axis and a torus around the equatorial plane. This orbital is also symmetrical about the Z-axis.

4. **Dxz Orbital**: The Dxz orbital is oriented between the X and Z axes. It has lobes extending in the X direction while being centered around the Z-axis. This orbital is not symmetrical about the Z-axis because it does not have equal distribution above and below the Z-axis.

### Step 2: Identify the Non-Symmetrical Orbital
From the analysis:
- Pz, S, and Dz² orbitals are symmetrical about the Z-axis.
- The Dxz orbital is not symmetrical about the Z-axis.

### Conclusion
Thus, the orbital that is not symmetrical about the Z-axis is the **Dxz orbital**.

### Final Answer
**The correct option is the Dxz orbital.**

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