Which of the following has regular tetrahedral structure?

Options

A. `BF_(4)^(-)`
B. `SF_(4)`
C. `XeF^(4)`
D. `[Ni(CN)_(4)]^(2-)`

Explanation

To determine which of the given compounds has a regular tetrahedral structure, we will analyze each compound step by step.

### Step 1: Analyze BF4⁻ (Boron Tetrafluoride Ion)
- **Hybridization**: To find the hybridization, we count the number of sigma bonds and lone pairs on the central atom (Boron).
- Boron forms 4 sigma bonds with 4 fluorine atoms and has no lone pairs.
- Hybridization = Number of sigma bonds + Number of lone pairs = 4 + 0 = 4.
- This corresponds to **sp³ hybridization**.
- **Geometry**: The sp³ hybridization indicates a tetrahedral geometry.

### Conclusion for BF4⁻:
- **Structure**: Regular tetrahedral.

### Step 2: Analyze SF4 (Sulfur Tetrafluoride)
- **Hybridization**: Sulfur forms 4 sigma bonds with 4 fluorine atoms and has 1 lone pair.
- Hybridization = 4 (sigma bonds) + 1 (lone pair) = 5.
- This corresponds to **sp³d hybridization**.
- **Geometry**: The presence of a lone pair results in a **seesaw** shape, not tetrahedral.

### Conclusion for SF4:
- **Structure**: Not tetrahedral.

### Step 3: Analyze XeF4 (Xenon Tetrafluoride)
- **Hybridization**: Xenon forms 4 sigma bonds with 4 fluorine atoms and has 2 lone pairs.
- Hybridization = 4 (sigma bonds) + 2 (lone pairs) = 6.
- This corresponds to **sp³d² hybridization**.
- **Geometry**: The presence of 2 lone pairs results in a **square planar** shape.

### Conclusion for XeF4:
- **Structure**: Not tetrahedral.

### Step 4: Analyze Ni(CN)₄²⁻ (Nickel Tetracyanide)
- **Hybridization**: Nickel is surrounded by 4 cyanide ligands, which are strong field ligands.
- Hybridization = 4 (sigma bonds) + 0 (lone pairs) = 4.
- This corresponds to **dsp² hybridization**.
- **Geometry**: The dsp² hybridization leads to a **square planar** geometry.

### Conclusion for Ni(CN)₄²⁻:
- **Structure**: Not tetrahedral.

### Final Answer:
After analyzing all the compounds, we conclude that **BF4⁻** is the only compound that has a regular tetrahedral structure.

### Summary:
- **Correct Answer**: BF4⁻ has a regular tetrahedral structure.