Question

Which of the following is valid at absolute zero

• A. Kinetic energy of the gas becomes zero but the molecular motion does not become zero
• B. Kinetic energy of the gas becomes zero and molecular motion also becomes zero
• C. Kinetic energy of the gas decreases but does not become zero
• D. Kinetic energy of the gas is maximum

Answer 1

The correct option is B Kinetic energy of the gas becomes zero and molecular motion also becomes zero

Kinetic Energy is directly proportional to temperature. With increase in temperature, kinetic energy increases. Consequently, the movement of the particles gets faster. Reverse phenomena is observed with decrease in temperature. At Absolute Zero temperature (−273.15°C), all the molecules are expected to have no kinetic energy and hence no molcecular motion. Absolute Zero is a theoretical value (it has never been reached).