Why do particles in a substance move faster when heat is added?

• A. Because heat decreases the potential energy of the particles.
• B. Because heat causes the particles to gain mass.
• C. Because heat changes the chemical identity of the particles.
• D. Because heat increases the kinetic energy of the particles.

Answer: (D)

Verified step by step guidance

1. Understand that heat is a form of energy transfer that affects the motion of particles in a substance.
2. Recall that the kinetic energy of particles is related to their motion; faster-moving particles have higher kinetic energy.
3. Recognize that when heat is added to a substance, energy is transferred to the particles, increasing their kinetic energy.
4. Know that an increase in kinetic energy means particles move faster, which can lead to changes in temperature or phase.
5. Note that heat does not change the mass or chemical identity of particles, nor does it decrease their potential energy in this context.