According to VSEPR THEORY

Options

A. the shape of the molecule depends upon the bonded electron pairs
B. pair of electrons attract each other in valence shells
C. the pairs of electrons tend to occupy such positions that minimise repulsions
D. the pairs of electrons tend to occupy such positions that minimise distances from each other.

Explanation

### Step-by-Step Solution:

1. **Understanding VSEPR Theory**:
- VSEPR stands for Valence Shell Electron Pair Repulsion theory. It is a model used to predict the geometry of individual molecules based on the number of electron pairs surrounding their central atoms.

2. **Key Assumption of VSEPR**:
- The fundamental assumption of VSEPR theory is that molecules adopt shapes that minimize the repulsion between the valence electron pairs of the atoms involved. This means that the electron pairs will arrange themselves as far apart from each other as possible.

3. **Electron Pair Arrangement**:
- The electron pairs can be either bonding pairs (shared between atoms) or lone pairs (not shared). The arrangement of these pairs determines the molecular geometry.

4. **Example of PF5**:
- Consider the molecule phosphorus pentafluoride (PF5). Phosphorus has 5 valence electrons, which it shares with 5 fluorine atoms.
- To minimize repulsion, the fluorine atoms are arranged in a trigonal bipyramidal geometry, where three fluorine atoms occupy equatorial positions and two occupy axial positions.

5. **Geometry of PF5**:
- In the trigonal bipyramidal structure, the equatorial fluorine atoms are spaced 120 degrees apart, while the axial fluorine atoms are positioned 180 degrees from each other. This arrangement minimizes the repulsion between the negatively charged electron pairs.

6. **Evaluating the Options**:
- The options presented in the question can be evaluated based on the principles of VSEPR theory:
- **Option A**: "The shape of the molecule depends upon the bonded electron pairs." - This is partially correct but does not encompass lone pairs which also affect shape.
- **Option B**: "Pairs of electrons attract each other in valence shells." - Incorrect, as electrons repel each other due to their negative charge.
- **Option C**: "Pairs of electrons tend to occupy such positions that minimize repulsion." - Correct, as this is the core principle of VSEPR theory.
- **Option D**: "The pairs of electrons tend to occupy such positions that minimizes distances from each other." - Incorrect, as minimizing distance would increase repulsion.

7. **Conclusion**:
- The correct answer is **Option C**: "Pairs of electrons tend to occupy such positions that minimize repulsion."