What is the temperature at which molecules have no kinetic energy and therefore cease to move?

What is the temperature at which molecules have no kinetic energy and therefore cease to move?

• A. Celestial zero
• B. Freezing point
• C. Absolute zero
• D. Thermal equilibrium

Answer: (C)

The correct answer is absolute zero, which is defined as the theoretical lowest temperature possible, where the motion of atoms and molecules comes to a standstill, resulting in zero kinetic energy. This temperature is 0 Kelvin, which is equivalent to -273.15 degrees Celsius or -459.67 degrees Fahrenheit. At absolute zero, particles occupy their lowest energy state, and classical mechanics predicts that there would be no thermal motion.

The other options do not accurately represent this concept. The freezing point refers to the temperature at which a substance changes from a liquid to a solid and does not imply the cessation of all molecular movement. Celestial zero is not a standard scientific term related to temperature. Thermal equilibrium refers to a state in which two bodies reach the same temperature, resulting in no net heat exchange, but does not indicate a complete stop in molecular motion.