Which statement correctly describes the particle arrangement in a solid?

Which statement correctly describes the particle arrangement in a solid?

• A. Particles are widely separated and move freely.
• B. Particles are tightly packed and vibrate in fixed positions.
• C. Particles flow and slide past each other.
• D. Particles move slowly but stay in place with no vibration.

Answer: (B)

In a solid, particles are tightly packed and held in place by strong forces, so they don’t flow. They only vibrate a little around fixed positions, which gives a solid its definite shape and volume. This is why the statement describing tightly packed particles that vibrate in fixed positions is the best description. The other ideas describe other states: a gas has widely separated particles that move freely, and a liquid’s particles can flow and slide past each other. The idea of particles moving slowly but staying in place with no vibration isn’t accurate for a solid, since there is always some vibration even when it feels still.

In a solid, particles are tightly packed and held in place by strong forces, so they don’t flow. They only vibrate a little around fixed positions, which gives a solid its definite shape and volume. This is why the statement describing tightly packed particles that vibrate in fixed positions is the best description. The other ideas describe other states: a gas has widely separated particles that move freely, and a liquid’s particles can flow and slide past each other. The idea of particles moving slowly but staying in place with no vibration isn’t accurate for a solid, since there is always some vibration even when it feels still.