Multiple choice:

Helium is an extremely inert (nonreactive) gas but it is not an ideal gas. How does helium, and all other real gases, differ from an ideal gas?

A. Real gas molecules have no volume

B. Real gas molecules are not in constant motion

C. Real gas molecules are attracted to each other

D. Real gas molecules do not exert pressure on the walls of a container

If butane gas in a rigid steel container is heated from 0 °C to 300 °C, which of the following will change the least?

A. The density of the butane gas

B. The average speed of the butane molecules

C. The average kinetic energy of the butane molecules

D. The force with which the butane molecules impact the cylinder walls