What is saturation vapor pressure?

Saturation vapor pressure refers to the pressure exerted by a vapor when it is in equilibrium with its liquid phase at a given temperature. This means that the rate of evaporation of the liquid is equal to the rate of condensation of the vapor, resulting in a stable state where the amount of vapor in the air remains constant. When vapor is in a saturated state, it can no longer hold more moisture without causing condensation.

At this point, the vapor pressure reflects the maximum amount of moisture that the air can hold at that temperature. As temperature increases, the saturation vapor pressure also increases, allowing the air to hold more water vapor. Therefore, the correct answer highlights the specific condition of pressure when the vapor is fully saturated, which plays a critical role in understanding concepts such as humidity, dew point, and precipitation.