The bond length and bond angles in molecules in the solid state are calculated by:

Options

A. (a) X-ray diffraction technique
B. (b) neutrons bombardment
C. (c) protons bombardment
D. (d) none of these

Answer

To solve the question regarding how bond lengths and bond angles in molecules in the solid state are calculated, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the methods used to calculate bond lengths and bond angles in solid-state molecules.

2. **Identifying the Techniques**: The options provided include:
- A) X-ray diffraction technique
- B) Neutron bombardment
- C) Proton bombardment

3. **Analyzing Option A - X-ray Diffraction Technique**:
- X-ray diffraction is a powerful technique used to study the arrangement of atoms within a crystal.
- When X-rays are directed at a crystal, they are scattered by the electrons surrounding the atoms.
- This scattering produces a diffraction pattern that can be analyzed to determine the three-dimensional arrangement of atoms in the crystal lattice.

4. **Calculating Bond Lengths and Angles**:
- From the 3D structure obtained through X-ray diffraction, one can derive the atomic and molecular structure of the crystal.
- The bond lengths (the distance between the nuclei of two bonded atoms) and bond angles (the angle formed between three atoms) can be calculated from this structural data.

5. **Analyzing Options B and C - Neutron and Proton Bombardment**:
- Neutron bombardment and proton bombardment are techniques primarily used in nuclear reactions and do not provide information about the atomic arrangement in a crystal lattice.
- These methods are not suitable for determining bond lengths and angles in solid-state molecules.

6. **Conclusion**: Based on the analysis, the correct method for calculating bond lengths and bond angles in solid-state molecules is the X-ray diffraction technique.

### Final Answer:
The bond length and bond angles in molecules in the solid state are calculated by **X-ray diffraction technique**.

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