Which statement best describes the significance of the temperature known as absolute zero?

• A. It is the temperature at which water freezes under standard atmospheric pressure.
• B. It is the temperature at which the energy of a system is at its maximum.
• C. It is the temperature at which gases become liquids.
• D. It is the temperature at which all molecular motion theoretically ceases.

Answer: (D)

Verified step by step guidance

1. Understand that absolute zero is a fundamental concept in thermodynamics and temperature scales.
2. Recall that temperature is related to the average kinetic energy of particles in a substance; higher temperature means higher particle motion.
3. Recognize that absolute zero is defined as the lowest possible temperature where the kinetic energy of particles reaches its minimum.
4. At absolute zero, molecular motion theoretically stops because particles have no thermal energy left to move.
5. Therefore, the significance of absolute zero is that it represents the temperature at which all molecular motion theoretically ceases.