Humidity refers to the amount of water vapor in the air. The warmer the air temperature, the more water vapor it can hold before reaching saturation. Cooler air temperatures cause water vapor molecules to slow down and condense together, forming liquid water droplets through the process of condensation. Relative humidity measures the current water vapor content compared to the maximum amount possible at a specific temperature before saturation is reached.

1. Humidity

2. Humidity - The amount of water vapor present in the air.

3. Air does not always contain the same amount of water vapor.

4. At warmer temperatures, the molecules of water vapor in air move quickly and don’t easily come together.

5. At cooler temperatures, molecules in air move more slowly.

6. The slower movement allows water vapor molecules to stick together and form droplets of liquid water.

7. Condensation - the formation of liquid water from water vapor.

8. HUMIDITY. =)

9. Relative Humidity

10. Relative Humidity - is a measure of the amount of water vapor present in the air compared to the amount needed for saturation at a specific temperature.

11. The amount of water vapor in the air at any given time is usually less than that required to saturate the air.

12. The most common units for vapor density are gm/m 3.

13. RELATIVE HUMIDITY SCALE. =)