Task: Question Answering
Input (English): Background Paragraph: Shown in the Figure below is a cylinder of gas on the left that is at room temperature (300 K). On the right, the cylinder has been heated until the Kelvin temperature has doubled to 600 K. The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles. Decreasing the temperature would have the opposite effect, and the pressure of an enclosed gas would decrease. 
Story: Nicholas works in pest control, and needs to have a steady supply of nitrogen gas for his tools. He always keeps a 
closed container of nitrogen gas in his freezer, where the temperature is very low.  Nicholas's neighbor, Justin, likes to grill in his backyard. Justin, therefore, always keeps a closed container of propane gas outside, where the temperature is high. 
Question: Molecules of which gas will collide against the walls of their respective container with more force?
Output (English): propane gas.