The characteristic features of solids are:

Options

A. Definite shape
B. Definite size
C. Definite shape and size
D. Definite shape, size and rigidity

Answer

**Step-by-Step Solution:**

1. **Definite Shape**: Solids have a fixed shape that does not change. This characteristic is particularly evident in crystalline solids, where the arrangement of molecules is orderly and consistent.

*Hint: Think about how a cube of ice retains its shape until it melts.*

2. **Definite Size**: Solids possess a definite volume and size. Unlike gases, which can expand to fill their container, solids maintain their volume regardless of the environment.

*Hint: Consider how a rock maintains its size whether it is in a small box or on the ground.*

3. **Rigidity**: Solids are rigid, meaning they resist deformation. This rigidity is due to the strong intermolecular forces that hold the molecules closely together, preventing them from moving freely.

*Hint: Imagine trying to compress a metal rod; it resists any change in shape.*

4. **Close Packing of Molecules**: In solids, especially crystalline solids, the molecules are packed closely together. This close packing contributes to the solidity and rigidity of the material.

*Hint: Think about how tightly packed marbles in a container are compared to the loose arrangement of balls in a box.*

5. **Intermolecular Forces**: The strong intermolecular forces in solids are responsible for their stability and fixed structure. These forces can be ionic, covalent, metallic, or van der Waals forces, depending on the type of solid.

*Hint: Reflect on how different types of bonds (like ionic vs. covalent) affect the properties of solids.*

**Final Answer**: The characteristic features of solids include definite shape, definite size, rigidity, close packing of molecules, and strong intermolecular forces.

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