Pressing the valve of a compressed–gas aerosol can allows gas to escape rapidly, and the can feels noticeably colder almost immediately. Which statement best explains this observation in terms of the properties of an ideal gas?
(a) Gas molecules lose kinetic energy through repeated inelastic collisions with the can’s metal walls, directly lowering the can’s temperature.
(b) Because pressure inside falls as gas escapes, and pressure is proportional to temperature, the pressure drop itself makes the remaining gas cool.
(c) The gas inside expands adiabatically when the valve is opened, so its temperature decreases; since pressure is roughly proportional to temperature, the pressure inside also drops, making the can feel cold.
(d) The mass of gas in the can decreases, and since pressure depends only on the amount of gas present, the temperature stays the same while the pressure falls.