1. Collisions of particles in a gas are called perfectly elastic collisions because:

A. the particles rebound in the direction from which they came
B. the gas exerts pressure on its container
C. there is no change in total kinetic energy
D. the particles bounce off the container walls

2. How is a column of mercury in a barometer affected when moved to a higher altiture?

A. the column of mercury will be greater than 760 mm Hg
B. the column of mercury will be less than 760 mm Hg
C. the altitude does not affect air pressure
D. the column of mercury will be the same because the temperature has not changed

3. When the temperature of a gas is increased,

A. the average kinetic energy of the gas particles decreases
B. the gas particles strike the sides of the container less often
C. the gas particles strike the sides of the container more often
D. the gas particles strike the sides of the container with inelastic collisions

4. When using an air pump to inflate a basketball, the average kinetic energy of the gas molecules within the pump _______ because the temperature _______.

A. increases;increases
B. decreases;decreases
C. increases;decreases
D. does not change;does not change