Read the passage given below and answer the following question
Ionic solids and melts are compounds in which the interactions are dominated by electrostatic effects. However, the polarization of the ions also plays an important role in many respects as has been clarified in recent years years thanks to the development of realistic polarizable interaction potentials. After detailing these models, we illustrate the importance of polarization effects on a series of examples concerning the structural properties, such as the stabilization of particular crystal structures or the formation of highly-coordinated multivalent ions in the melts, as well as the dynamic properties such as the diffusion of ionic species. The effect on the structure of molten salt interfaces (with vacuum and electrified metal) is also described. Although most of the results describes here concern inorganic compounds (mol,yen fluorides and chlorides, ionic oxides.....), the particular case of the room temperature ionic liquids, a special class of molten salts in which at least one species is organic, will also be briefly discussed to indicate how the ideas gained from the study of 'simple' molten salts are being transferred to these more complex systems.
Source : https:`////`www.landfonline.com`//`doi`//`abs`//`10.1080`//`00268976.2011.617523
Which statement is incorrect about crystalline solids ?

Options

A. They have long range order
B. They have definite melting point
C. They are rigid and compressible
D. They break into two pieces with irregular surface

Answer

To determine which statement is incorrect about crystalline solids, let's analyze the characteristics of crystalline solids based on the information provided in the passage and the video transcript.

### Step-by-Step Solution:

1. **Understanding Crystalline Solids**:
- Crystalline solids are materials whose constituents (atoms, molecules, or ions) are arranged in a highly ordered structure, forming a crystal lattice that extends in all three spatial dimensions.

**Hint**: Remember that the arrangement of particles in crystalline solids is regular and repeating.

2. **Long Range Order**:
- Crystalline solids exhibit long-range order due to their regular arrangement. This means that if you look at any section of the solid, it will have the same structure as any other section.

**Hint**: Think about how the regular pattern continues indefinitely in crystalline solids.

3. **Definite Melting Point**:
- Because of their ordered structure, crystalline solids have a specific melting point. When they melt, they transition from a solid to a liquid at a precise temperature.

**Hint**: Consider how the uniform structure affects the energy required to break the bonds during melting.

4. **Rigidity and Compressibility**:
- Crystalline solids are generally rigid due to the strong intermolecular forces holding the particles in place. However, they are not compressible because there is very little space between the particles.

**Hint**: Reflect on how the lack of space between particles affects their ability to be compressed.

5. **Breaking into Pieces**:
- When crystalline solids break, they tend to fracture along specific planes, resulting in surfaces that are often smooth and regular, rather than irregular.

**Hint**: Think about how the regular structure would influence the way a solid breaks.

### Conclusion:
Based on the analysis, the incorrect statements about crystalline solids are:

- **They are rigid and compressible** (This statement is incorrect; they are rigid but not compressible).
- **They break into two pieces with irregular surface** (This statement is also incorrect; they break along regular planes).

### Final Answer:
The incorrect statements about crystalline solids are:
1. They are rigid and compressible.
2. They break into two pieces with irregular surface.