Which statement best describes the difference between heat and thermal energy?

• A. Heat and thermal energy are identical and can always be used interchangeably.
• B. Thermal energy is the total kinetic energy of particles in a substance, while heat is the transfer of thermal energy between objects due to a temperature difference.
• C. Heat is the energy stored within chemical bonds, while thermal energy is the energy transferred during a chemical reaction.
• D. Thermal energy only exists in solids, while heat only exists in liquids and gases.

Answer: (B)

Verified step by step guidance

1. Understand the definitions of thermal energy and heat: Thermal energy refers to the total kinetic energy of all the particles in a substance due to their random motion.
2. Recognize that heat is not energy contained within an object, but rather the energy transferred between objects because of a temperature difference.
3. Note that thermal energy depends on the temperature and the amount of substance, as it is the sum of kinetic energies of particles.
4. Heat, on the other hand, is energy in transit and flows from a hotter object to a cooler one until thermal equilibrium is reached.
5. Therefore, the key difference is that thermal energy is the energy contained within a substance, while heat is the process of energy transfer between substances.