Which of the following best describes what temperature measures?

• A. The total amount of heat contained in a substance
• B. The mass of the particles in a substance
• C. The average kinetic energy of the particles in a substance
• D. The rate at which a chemical reaction occurs

Answer: (C)

Verified step by step guidance

1. Understand that temperature is a physical quantity related to the motion of particles in a substance.
2. Recall that heat is the total energy transferred due to temperature difference, not the temperature itself.
3. Recognize that the mass of particles does not define temperature; rather, temperature depends on how fast particles move on average.
4. Know that the rate of a chemical reaction is influenced by temperature but is not what temperature measures.
5. Conclude that temperature measures the average kinetic energy of the particles in a substance, reflecting how energetically they move.