Which term is the measure of the average kinetic energy of a substance's molecules?

Which term is the measure of the average kinetic energy of a substance's molecules?

• A. Temperature
• B. Heat Transfer
• C. Thermal Energy
• D. Kinetic Energy

Answer: (A)

Temperature is a measure of the average kinetic energy of a substance's molecules. As a substance warms, its molecules move faster on average, so their average kinetic energy increases. Temperature captures this overall, collective motion of all the molecules, and in many cases is directly related to that average kinetic energy (for example, for an ideal gas, the average translational kinetic energy is proportional to temperature). Heat transfer is the process of energy moving between objects due to a temperature difference, not a measure of energy content. Thermal energy is the total internal energy from all molecular motion and interactions in the substance, depending on how many particles are present. Kinetic energy is the energy of motion for individual molecules, which contributes to temperature but does not by itself describe the average energy of all molecules in the system.

Temperature is a measure of the average kinetic energy of a substance's molecules. As a substance warms, its molecules move faster on average, so their average kinetic energy increases. Temperature captures this overall, collective motion of all the molecules, and in many cases is directly related to that average kinetic energy (for example, for an ideal gas, the average translational kinetic energy is proportional to temperature).

Heat transfer is the process of energy moving between objects due to a temperature difference, not a measure of energy content. Thermal energy is the total internal energy from all molecular motion and interactions in the substance, depending on how many particles are present. Kinetic energy is the energy of motion for individual molecules, which contributes to temperature but does not by itself describe the average energy of all molecules in the system.