Describe the arrangement, movement and energy of particles in a solid.

• A. Random arrangement, random movement, high energy.
• B. Regular arrangement, no movement, low energy.
• C. Random arrangement, some movement, medium energy.
• D. Regular arrangement, random movement, high energy.

Answer: (A)

In a solid, particles sit in a regular, orderly lattice and stay in fixed positions, only vibrating a little about those points. Because they’re held together by strong forces, the energy is low compared with liquids or gases. So the description that fits best is a regular arrangement with very little movement and low energy. The idea of random arrangement describes liquids or gases, and “random movement” would imply particles moving freely rather than staying in fixed positions, while high energy would suggest a more energetic state than a solid.