Chapter 22 Section 1 Chapter 22 Section 1 Review Page 554 (1-8)Review Page 554 (1-8)

1. 1. Describe the Describe the composition of dry air composition of dry air at sea level.at sea level.

• Nitrogen = 78%Nitrogen = 78%

• Oxygen = 21%Oxygen = 21%

• Argon = 0.9%Argon = 0.9%

• Other gases (like COOther gases (like CO2 2 < 0.1% < 0.1%

Gases in the AtmosphereGases in the Atmosphere

2. 2. Identify five main Identify five main components of the components of the atmosphere.atmosphere.

• NitrogenNitrogen• OxygenOxygen• Water VaporWater Vapor• OzoneOzone• ParticulatesParticulates

ParticulatesParticulates

3. 3. Explain the cause of Explain the cause of atmospheric pressure.atmospheric pressure.

• Atmospheric pressure is caused Atmospheric pressure is caused by the weight of atmospheric by the weight of atmospheric gases as a result of gravity gases as a result of gravity pulling the gas molecules toward pulling the gas molecules toward Earth.Earth.

Atmospheric PressureAtmospheric Pressure

4. 4. Explain how the two Explain how the two types of barometers types of barometers measure atmospheric measure atmospheric pressure.pressure.

• Mercurial Barometer: Mercurial Barometer: Atmospheric pressure pushes on Atmospheric pressure pushes on the well at the base of the the well at the base of the barometer. This holds the level barometer. This holds the level of the mercury in the tube at a of the mercury in the tube at a height indicating the air height indicating the air pressure.pressure.

Mercury BarometerMercury Barometer

Mercury BarometerMercury Barometer

4. 4. Explain how the two Explain how the two types of barometers types of barometers measure atmospheric measure atmospheric pressure.pressure.

• Aneroid Barometer: Atmospheric Aneroid Barometer: Atmospheric pressure pushes in on the side of pressure pushes in on the side of a sealed metal container causing a sealed metal container causing the sides of the container to the sides of the container to bulge in or out, moving the bulge in or out, moving the pointer on a scale showing the pointer on a scale showing the air pressure.air pressure.

Aneroid BarometerAneroid Barometer

5. 5. Identify the layer of Identify the layer of the atmosphere in the atmosphere in which weather occurs.which weather occurs.

• Weather happens in the Weather happens in the troposphere.troposphere.

Weather Weather in the in the

TropospherTropospheree

6. 6. Compare the four Compare the four main layers of the main layers of the atmosphere.atmosphere.

• TroposphereTroposphere: lowest layer, weather : lowest layer, weather happens here, highest pressurehappens here, highest pressure

• StratosphereStratosphere: second layer, contains : second layer, contains the ozone layer, gets warmer as you the ozone layer, gets warmer as you go upgo up

• MesosphereMesosphere: coldest layer, meteors : coldest layer, meteors burn up here, gets colder as you go upburn up here, gets colder as you go up

• ThermosphereThermosphere: hottest layer, : hottest layer, ionosphere is here so auroras happen ionosphere is here so auroras happen here, hottest layer, lowest air here, hottest layer, lowest air pressure (near zero)pressure (near zero)

Layers of the AtmosphereLayers of the Atmosphere

7. 7. Identify the two Identify the two atmospheric layers atmospheric layers that contain air as that contain air as warm as 25warm as 2500 C? C?

• The The tropospheretroposphere and the and the

thermospherethermosphere

Temperature Ranges of LayersTemperature Ranges of Layers25o C25o C

Thermosphere

Troposphere

8. 8. Why is atmospheric Why is atmospheric pressure generally lower pressure generally lower beneath a mass of warm air beneath a mass of warm air than beneath a mass of than beneath a mass of cold air?cold air?

•Molecules move farther apart Molecules move farther apart when they are heated, so when they are heated, so there are fewer particles in a there are fewer particles in a given area to exert pressure.given area to exert pressure.

Cause of Atmospheric Cause of Atmospheric PressurePressure

The End…..The End…..