What happens to particle speed as temperature increases?

• A. They move slower
• B. They stop moving
• C. They move at constant speed
• D. They move faster

Answer: (D)

Temperature relates to how much energy particles have. When temperature goes up, particles gain energy and, on average, move faster. This applies across states of matter: in gases, speeds rise and collisions become more energetic; in liquids and solids, particles vibrate more quickly. Individual particles vary in speed, but the overall average speed increases with temperature. So, as temperature increases, they move faster. The ideas of moving slower, stopping, or keeping constant speed don’t align with adding energy to the system.