Vapor pressure is the pressure exerted by a vapor when condensation:

A. <
B. =
C. >
evaporation over its liquid in a closed system.

and your thinking is?

i think its B b/c the rates of condensation and evaporation should be equal?

am i correct???

Yes.

The correct answer is A. < (less than).

To understand why, we need to first understand the concept of vapor pressure. Vapor pressure is the pressure exerted by a vapor when it is in equilibrium with its liquid phase in a closed system.

When a liquid is placed in a closed container, its molecules are constantly in motion. Some of these molecules have enough energy to break free from the liquid and escape into the gas phase, which is called evaporation. However, at the same time, some of the molecules in the gas phase collide with the liquid surface and return to the liquid phase, which is known as condensation.

In equilibrium, the rate of evaporation equals the rate of condensation, meaning that the number of molecules leaving the liquid phase is equal to the number of molecules returning to the liquid phase. This is when the vapor pressure is reached.

If the vapor pressure is less than the external pressure (which is usually the atmospheric pressure in most cases), then condensation will occur. This happens because the pressure exerted by the vapor is not strong enough to overcome the external pressure, causing the gas molecules to return to the liquid phase. Thus, the vapor pressure is smaller than the external pressure, and the correct answer is A. <.