Which of the following statements is not correct about the three states of matter, i.e., solid, liquids and gas?

Options

A. Molecules of a solid possess least energy whereas those of a gas possesss highest energy
B. The density of solids is highest whereas that of gases is lowest
C. Gases and liquids possess definite volumes
D. Molecules of a solids possess vibratory motion

Answer

To determine which statement is not correct about the three states of matter (solid, liquid, and gas), let's analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Molecules of a solid possess least energy where those of gas possess highest energy.**
- **Analysis:** In solids, molecules are closely packed and have limited movement, resulting in low kinetic energy. In gases, molecules are far apart and move rapidly, resulting in high kinetic energy.
- **Conclusion:** This statement is correct.

2. **Statement 2: The density of solid is highest where that of gas is lowest.**
- **Analysis:** Density is defined as mass per unit volume. Solids have closely packed molecules, leading to higher mass in a given volume compared to gases, which have widely spaced molecules and therefore lower mass in the same volume.
- **Conclusion:** This statement is correct.

3. **Statement 3: Gas and liquid possess definite volume.**
- **Analysis:** Liquids have a definite volume; they maintain the same volume regardless of the container. However, gases do not have a definite volume; they expand to fill the entire volume of their container.
- **Conclusion:** This statement is incorrect.

4. **Statement 4: Molecules of the solid possess vibrational motion.**
- **Analysis:** In solids, molecules do exhibit vibrational motion as they oscillate about their fixed positions, although they do not move freely as in liquids or gases.
- **Conclusion:** This statement is correct.

### Final Answer:
The statement that is not correct is: **Gas and liquid possess definite volume.**

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