Chapter 22 Section 1 Review Page 554 (1-8) 1. Describe the composition of dry air at sea level. • Nitrogen = 78% • Oxygen = 21% • Argon = 0.9% • Other gases (like CO2 < 0.1% Gases in the Atmosphere 2. Identify five main components of the atmosphere. • Nitrogen • Oxygen • Water Vapor • Ozone • Particulates Particulates 3. Explain the cause of atmospheric pressure. • Atmospheric pressure is caused by the weight of atmospheric gases as a result of gravity pulling the gas molecules toward Earth. Atmospheric Pressure 4. Explain how the two types of barometers measure atmospheric pressure. • Mercurial Barometer: Atmospheric pressure pushes on the well at the base of the barometer. This holds the level of the mercury in the tube at a height indicating the air pressure. Mercury Barometer Mercury Barometer 4. Explain how the two types of barometers measure atmospheric pressure. • Aneroid Barometer: Atmospheric pressure pushes in on the side of a sealed metal container causing the sides of the container to bulge in or out, moving the pointer on a scale showing the air pressure. Aneroid Barometer 5. Identify the layer of the atmosphere in which weather occurs. • Weather happens in the troposphere. Weather in the Troposphere 6. Compare the four main layers of the atmosphere. • Troposphere: lowest layer, weather happens here, highest pressure • Stratosphere: second layer, contains the ozone layer, gets warmer as you go up • Mesosphere: coldest layer, meteors burn up here, gets colder as you go up • Thermosphere: hottest layer, ionosphere is here so auroras happen here, hottest layer, lowest air pressure (near zero) Layers of the Atmosphere 7. Identify the two atmospheric layers that contain air as warm as 250 C? • The troposphere and the thermosphere Temperature Ranges of Layers 25o C 25o C Thermosphere Troposphere 8. Why is atmospheric pressure generally lower beneath a mass of warm air than beneath a mass of cold air? • Molecules move farther apart when they are heated, so there are fewer particles in a given area to exert pressure. Cause of Atmospheric Pressure The End…..