Final answer:
The ratio of water in the air to the maximum amount of water vapor it can hold at a given temperature is called relative humidity. If the air's water vapor content equals the saturation density at a certain temperature, the relative humidity is 100%. Otherwise, the relative humidity is calculated by dividing the water vapor density by the saturation vapor density at that temperature and multiplying by 100%.
Step-by-step explanation:
The ratio of water in the air compared to the maximum amount of water vapor the air can hold at a given temperature is known as the percent relative humidity. This can be calculated if we know both the current water vapor density and the saturation vapor density at a certain temperature. For instance, if the air contains 9.40 g/m³ of water vapor and this is the saturation density at 10.0°C, then the relative humidity at this temperature is 100%. However, at a higher temperature where air can hold more water vapor, the percent relative humidity will be less than 100%. This concept is vital in understanding weather phenomena, drying processes, and the behavior of water vapor in various temperatures. For example, if we know the air at 25.0°C has a saturation vapor density of 23.0 g/m³ and contains 9.40 g/m³ of water vapor, we can calculate the relative humidity at this temperature. To do so, we divide the amount of water vapor present (9.40 g/m³) by the maximum amount it could hold at that temperature (23.0 g/m³) and multiply by 100%, yielding a relative humidity percentage.