In the solid state, __________ .

• A. atoms or molecules have a lot of space between them
• B. atoms or molecules pack closely but move freely
• C. atoms or molecules pack closely in fixed locations
• D. matter has a fixed volume but not a fixed shape

Answer: (C)

Verified step by step guidance

1. Understand the properties of solids: In the solid state, matter has a fixed volume and a fixed shape. This is because the atoms or molecules are closely packed together in a regular pattern.
2. Recognize the arrangement of particles: In solids, atoms or molecules are arranged in a fixed, orderly pattern, which restricts their movement to only vibrations about fixed positions.
3. Differentiate from other states: Unlike liquids and gases, solids do not have particles that move freely. In liquids, particles are close but can move past each other, and in gases, particles are far apart and move freely.
4. Consider the implications of particle arrangement: The close packing of particles in solids results in a definite shape and volume, which is why solids do not conform to the shape of their container like liquids or gases do.
5. Summarize the key concept: In the solid state, atoms or molecules pack closely in fixed locations, leading to a fixed shape and volume, distinguishing solids from liquids and gases.