What does the particle model say about temperature increase?

• A. Particles lose energy and slow down.
• B. Dissociation of molecules occurs.
• C. Collisions cease.
• D. Particles gain energy, move faster, leading to more collisions.

Answer: (D)

Temperature reflects the average kinetic energy of particles. When temperature rises, particles gain energy and move faster, which leads to more frequent and more energetic collisions. This explains why heating a gas increases its pressure at a fixed volume and can speed up chemical reactions. The other ideas don’t fit: a temperature rise doesn’t cause particles to lose energy or for collisions to stop, and while high temperatures can break bonds in some cases, that’s not the general consequence of a temperature increase.