How would you use the kinetic theory to explain why a helium filled balloon "shrinks" when it is taken from a warm room to the outside on a cold day?
From kinetic theory, the pressure can be interpreted as, 2/3 the kinetic energy of molecules per unit volume.
Also, from kinetic interpretation of temperature, the ideal gas molecules have their energy proportional to the absolute temperature.
Combining the two relations,
Then for a decrease in temperature
This explains why the balloon shrinks when the temperature decreases.