a vapor material exerts a pressure or force in which way?

Answer 1

The molcules inside of a liquid attract each other from every direction.

But the molecules at the surface of the liquid have an upward force which is not affected by other liquid molecules above. (The molecules are still attracted from below).This upwards force is vapor pressure.

the vapor pressure will increase as the temp. rises, because the molecules have more energy.

When vapor pressure equals the atmospheric pressure, the substance is boiling.