Absolute zero is zero on the what scale?

-273 0C that is equal to 0 Kelvin.

Although "absolute zero" is expressed on all three major temperature scales, it represents the lowest temperature on the Kelvin scale (0° K).

−273.15°C

Temperature is a measure of the vibrational energy of an atom. Vibration gives rise to pressure of a gas and hence it's volume. Reducing the temperature slows this atomic vibration and the volume...

Absolute zero is zero Kelvin.