Question

how would you determine the absolute zero temperature?
a) measure it using a mercury thermometer at the temperature that nitrogen boils
b) measure it using a gas thermometer at zero pressure
c) approach it using a gas thermometer at very low pressure

Explanation:

Absolute zero is the lowest possible temperature where the kinetic energy of gas molecules approaches zero. A gas thermometer at very low pressure can be used to approach and estimate absolute - zero temperature. Mercury thermometers are not suitable for such low temperatures as mercury freezes well above absolute zero, and zero pressure in a gas thermometer is not physically attainable.

Answer:

C. Approach it using a gas thermometer at very low pressure