The correct option is **B**: Particles in a solid are closely packed and vibrate in fixed positions, while particles in a liquid are close together but can move past one another. ### Detailed Explanation 1. **Understanding the States of Matter**: - Matter exists in different states: solid, liquid, and gas. The arrangement and movement of particles in these states determine their properties. 2. **Arrangement of Particles in a Solid**: - In solids, particles are arranged in a tightly packed structure, often in a regular pattern. This close packing is due to strong intermolecular forces that hold the particles together. - The particles in a solid do not have the freedom to move around; instead, they can only vibrate in place. This limited movement is what gives solids their definite shape and volume. 3. **Arrangement of Particles in a Liquid**: - In liquids, the particles are also closely packed, but the intermolecular forces are weaker than in solids. This allows the particles to move past one another, which is why liquids can flow and take the shape of their container. - While the particles in a liquid are still relatively close together, they are not fixed in position like in solids. This ability to move gives liquids a definite volume but no definite shape. 4. **Why Option B is Correct**: - Option B accurately describes the characteristics of solids and liquids. It highlights that solids have closely packed particles that vibrate in fixed positions, while liquids have closely packed particles that can move past each other. This distinction is crucial in understanding the fundamental differences between these two states of matter. ### Why the Other Options are Incorrect - **Option A**: "Particles in a solid are free to move and are far apart, while particles in a liquid are closely packed and vibrate in fixed positions." - This statement is incorrect because it misrepresents the behavior of particles in solids. In solids, particles are not free to move; they are fixed in place and can only vibrate. Additionally, particles in solids are not far apart; they are closely packed. - **Option C**: "Particles in a solid are randomly arranged and can flow easily, while particles in a liquid are rigid and cannot move." - This option is incorrect because it describes solids as having a random arrangement, which is not true. Solids have a well-defined, ordered arrangement of particles. Furthermore, solids cannot flow easily; they maintain a fixed shape. Liquids, on the other hand, can flow and are not rigid. - **Option D**: "Particles in a solid have high kinetic energy, while particles in a liquid have low kinetic energy." - This statement is misleading. While it is true that particles in a solid have lower kinetic energy compared to those in a liquid, it does not accurately describe the arrangement of particles. Solids have lower kinetic energy because their particles are not moving freely, while liquids have higher kinetic energy, allowing their particles to move past one another. ### Summary of Key Points - **Solid Particles**: Closely packed, vibrate in fixed positions, definite shape and volume. - **Liquid Particles**: Closely packed but can move past one another, definite volume but no definite shape. - **Key Differences**: Solids are rigid and maintain shape; liquids can flow and take the shape of their container. - **Understanding States of Matter**: Recognizing the arrangement and movement of particles is essential for distinguishing between solids and liquids. This understanding is fundamental in physics and helps explain many physical properties and behaviors of materials in different states.