Which of the following best describes temperature in terms of particle behavior?

• A. It is a measure of the total potential energy of all the particles in a substance.
• B. It is a measure of the total kinetic energy of all the particles in a substance.
• C. It is a measure of the average potential energy of all the particles in a substance.
• D. It is a measure of the average kinetic energy of all the particles in a substance.

Answer: (D)

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 particles in matter have both kinetic energy (due to motion) and potential energy (due to position and interactions).
3. Recognize that temperature specifically correlates with the average kinetic energy of the particles, not their potential energy or total energy.
4. Express this relationship mathematically: the average kinetic energy per particle is proportional to temperature, given by \(\langle KE \rangle = \frac{3}{2} k_B T\), where \(k_B\) is Boltzmann's constant and \(T\) is the temperature in kelvins.
5. Conclude that temperature measures how fast particles are moving on average, which corresponds to their average kinetic energy.