Absolute Zero

Absolute zero is defined as 0 K ($-273$ $^\circ$C). At this temperature, particles have the minimum possible kinetic energy. No substance can be cooled below absolute zero.

The Kelvin temperature scale uses absolute zero as its starting point. This makes it essential for gas law calculations, where using Celsius would give incorrect results because 0 $^\circ$C does not represent zero particle energy.

$T(\text{K}) = \theta(^\circ\text{C}) + 273$