Which of the following best describes what happens as matter changes state from gas to liquid?

• A. The chemical composition of the substance changes.
• B. The particles gain energy and move farther apart.
• C. The particles lose energy and move closer together.
• D. The process is always irreversible.

Answer: (C)

Verified step by step guidance

1. Understand that changing state from gas to liquid is a physical change, not a chemical change, so the chemical composition of the substance remains the same.
2. Recall that in the gas phase, particles have high kinetic energy and are far apart, moving freely.
3. When a gas condenses to a liquid, the particles lose energy, which means their kinetic energy decreases.
4. As the particles lose energy, they move closer together because the attractive forces between them become more significant.
5. Recognize that this process is generally reversible by adding energy (e.g., heating the liquid to vaporize it back to gas).