Question

When the temperature of a substance is increased:

• A. Kinetic energy of the molecules of the substance increases.
• B. Kinetic energy of the molecules of the substance decreases.
• C. The amplitude of vibrations of molecules of the substance about their mean position decreases
• D. It does not show any change.

Answer 1

The correct option is A Kinetic energy of the molecules of the substance increases.

When the temperature of a substance is increased, i.e., if you double the Kelvin temperature of a substance, you double the average kinetic energy of its molecules. When the average kinetic energy of the molecules goes up (a rise in temperature), the average speed of the molecules increases.