Which statement best describes the molecules in a solid?

• A. The molecules are far apart and move freely in all directions.
• B. The molecules are randomly scattered and have no definite arrangement.
• C. The molecules are loosely arranged and slide past one another.
• D. The molecules are closely packed together and vibrate in fixed positions.

Answer: (D)

Verified step by step guidance

1. Understand the characteristics of solids: In a solid, molecules are tightly packed together in a fixed, orderly arrangement.
2. Recall molecular motion in solids: Molecules in solids do not move freely; instead, they vibrate around fixed points without changing their positions.
3. Compare with other states of matter: Unlike gases where molecules move freely and are far apart, or liquids where molecules slide past each other, solids have molecules that are closely packed and fixed.
4. Analyze each statement: Identify which description matches the behavior of molecules in solids based on their arrangement and motion.
5. Conclude that the correct description is: 'The molecules are closely packed together and vibrate in fixed positions,' because this accurately reflects the molecular structure and dynamics of solids.