Absolute Zero: This is theoretically the lowest possible temperature, where particles have minimum kinetic energy. It's equivalent to -273.15°C or 0 Kelvin.
Atmospheric Pressure: The force exerted by the weight of the atmosphere, which at sea level has a mean value of one atmosphere and gradually decreases with increasing altitude.
Kelvin Scale: An absolute temperature scale starting at absolute zero, where particles have minimum kinetic energy, and going up in increments based on the Celsius scale.