At absolute zero temperature, particles don't possess any motion. Hence, no kinetic energy will be there. Absolute zero is where the kinetic energy of the particles is zero. That means all the motion between particles will cease. At a temperature of zero Kelvin (absolute zero), the atoms of a substance have minimal kinetic energy. The Kelvin temperature scale is the SI reference unit for temperature measurement. All molecular motion does not cease at absolute zero (molecules vibrate with what is called zero-point energy), but no energy from molecular motion is available for transfer to other systems, and it is therefore correct to say that the energy at absolute zero is minimal. It is not possible to go below absolute zero because the thermal motion of gas molecules ceases at absolute zero.