Absolute zero
Definition
Absolute zero is the lowest possible temperature where all molecular motion ceases. It is 0 Kelvin, or -273.15 degrees Celsius.
5 Must Know Facts For Your Next Test
- Absolute zero is the theoretical temperature at which a system's entropy would reach its minimum value.
- At absolute zero, the thermal motion of particles in a substance would be minimal, but quantum mechanical effects still persist.
- It is not possible to reach absolute zero exactly due to the Third Law of Thermodynamics.
- Absolute zero serves as a reference point on the Kelvin temperature scale, which is an absolute thermodynamic scale.
- $0$ K equals $-273.15^{\circ}$C and $-459.67^{\circ}$F.
Review Questions
- What happens to molecular motion at absolute zero?
- Why can't we reach absolute zero according to the Third Law of Thermodynamics?
- Convert $0$ K to Celsius and Fahrenheit.
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Related terms
Kelvin: A unit of measure for temperature based on an absolute scale where $0$ K is absolute zero.
Third Law of Thermodynamics: States that as the temperature approaches absolute zero, the entropy of a system approaches a constant minimum.
Entropy: A measure of disorder or randomness in a system; it tends to decrease as temperature lowers towards absolute zero.
