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

• A. Thermal energy and heat are both forms of energy that can be measured in joules and are always the same.
• 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. Thermal energy refers to energy transfer, while heat is the energy contained within a substance.
• D. Heat is stored within an object, while thermal energy is only present during energy transfer.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definitions of thermal energy and heat. Thermal energy is the total kinetic energy of all the particles in a substance, which depends on the temperature and the amount of substance.
2. Step 2: Recognize that heat is not energy contained within an object, but rather the energy that is transferred between objects due to a temperature difference.
3. Step 3: Differentiate between the two concepts: thermal energy is a property of the substance itself, while heat describes the process of energy transfer.
4. Step 4: Note that both thermal energy and heat are measured in joules, but they represent different physical ideas—thermal energy is stored energy, heat is energy in transit.
5. Step 5: Conclude that the best description is: 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.