Why are solids able to maintain a fixed shape?

• A. Because the particles in a solid move freely and randomly.
• B. Because solids have a variable volume that adapts to their container.
• C. Because the particles in a solid are closely packed and vibrate in fixed positions.
• D. Because solids have no intermolecular forces between their particles.

Answer: (C)

Verified step by step guidance

1. Understand the nature of particle arrangement in solids: In solids, particles (atoms, ions, or molecules) are packed very closely together in a fixed, orderly pattern.
2. Recognize the type of motion particles exhibit in solids: Unlike gases or liquids, particles in solids do not move freely or randomly; instead, they vibrate around fixed positions.
3. Consider the role of intermolecular forces: Strong intermolecular forces hold the particles tightly in place, preventing them from moving past each other and thus maintaining a fixed shape.
4. Contrast solids with other states of matter: Liquids and gases have particles that move more freely, allowing them to change shape and volume, whereas solids resist shape changes due to their fixed particle positions.
5. Conclude that the fixed shape of solids arises because their particles are closely packed and only vibrate in place, which keeps the solid's shape constant.