. . . "a given sample of gas at constant temperature varies inversely with the pressure ??? ??? ??? absolute zero -273 C is the lowest point, when converted to Kelvin, is 0. cannot be lower than this on Kelvin scale ??? ??? ??? Charles's law The volume of a given sample of gas at constant pressure is directly proportional to the temperature in kelvins ??? ??? ??? Avogadro's Law Equal volumes of gases at" .