Water in the Atmosphere

Matching Condensation The process by which water vapor becomes liquid water. Evaporation The process by molecules of liquid water escape into the air after becoming water vapor. Humidity A measure of the amount of water vapor in the air. Psychrometer An instrument for measuring relative humidity. Relative Humidity A percentage comparing the amount of water vapor in the air to the maximum amount of water vapor the air can hold at a particular temperature. Fill in the Blanks 1. In the water cycle, precipitation in the form of rain or snow falls from the clouds.2. Water returns to the atmosphere as vapor by the process of evaporation.3. Water vapor in the atmosphere condenses to form clouds.4. We learned that cool air can hold less water than warm air.5. At 10ºC, 1 cubic meter of air can hold 8 grams of water vapor. If the air had 2 grams of vapor, the relative humidity would be 25%. Relative Humidity The readings on a psychrometer for the dry-bulb thermometer and the wet-bulb thermometer are shown below. Use the chart to fill in the table on relative humidity. Dry Bulb Temp. Wet Bulb Temp. Difference between Wet Dry Bulbs Relative Humidity (%) 19 16 3 74 29 25 4 72 12 11 1 89 28 23 5 65 14 11 3 70 30 29 1 93 11 10 1 89 17 15 2 81 22 17 5 61 *Using the information provided, fill in the table below. Dry Bulb Temp. Wet Bulb Temp. Difference between Wet Dry Bulbs Relative Humidity (%) 19 17 2 82 13 9 4 59 27 24 3 78 15 10 5 53