What is the theoretical point where all molecular motion stops, known as 0 Degree Kelvin?

The theoretical point where all molecular motion stops is known as absolute zero. At this temperature, which is equivalent to 0 Kelvin, the kinetic energy of particles reaches its minimum value, meaning that molecular motion ceases entirely. This concept is fundamental in thermodynamics and physics, reflecting the lowest possible temperature limit.

Absolute zero is defined as 0 Kelvin, which corresponds to -273.15 degrees Celsius and -459.67 degrees Fahrenheit. It represents a state in which the entropy of a perfect crystalline substance reaches its minimum value according to the third law of thermodynamics.

The other options represent different concepts: the freezing point refers to the temperature at which a substance transitions from a liquid to a solid; Celsius point is a way of denoting temperatures in the Celsius scale, which is commonly used for everyday temperature measurements; liquid helium point denotes the temperature at which helium becomes a liquid, typically around 4.2 Kelvin at atmospheric pressure, but still above absolute zero.