The Atmosphere

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The Atmosphere
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atmosphere

• definition the layer of gases that surrounds
  the Earth
• weather the condition of Earths atmosphere at
  any given time or place

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What gases are in our atmosphere?

• nitrogen (N2) 78
• oxygen (O2) 21
• trace gases 1
• argon
• CO2
• neon
• methane
• krypton
• hydrogen

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What are some sources of carbon dioxide (CO2) in
our atmosphere?

• burning fossil fuels releases CO2
• into the atmosphere
• Greenhouse Effect- CO2 and other gases act as a
  blanket to hold in heat close to Earth

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What else is in our atmosphere?

• Water vapor- from evaporation and transpiration
  (1 tree gives off 40,000 gallons of water vapor
  in a year!)
• Solid particles (particulate matter)- dust,
  smoke, pollen, salt, NOX, VOX- from car
  exhaust, burning and volcanic eruptions

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ozone

• O3- a form of oxygen with 3 atoms of oxygen
  instead
• of 2
• the layer of ozone
• in the atmosphere
• absorbs UV
• radiation from
• the sun and heats
• the Earth

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Learn more about the ozone layer

• http//www.brainpop.com/science/earthsystem/ozonel
  ayer/

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air pressure

• definition- the weight of a column of air pushing
  down on an area
• More dense air has higher air pressure than less
  dense air.
• barometer- an instrument used to measure air
  pressure

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air pressure animation

• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es1901/es1901page01.cfm?cha
  

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units for measuring air pressure

• inches of mercury- used
• with a mercury barometer
• millibars- used on National
• Weather
• Service maps

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altitude

• definition- the distance above sea level
• The higher the altitude the lower the air
  pressure.
• animation http//www.phschool.com/webcodes10/ind
  ex.cfm?fuseactionhome.gotoWebCode

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properties of air

• 1. mass- even though you cant see it, air has
  mass
• How much mass did our balloon have?
• How much mass did it have with air blown inside?
• How much was the mass of the air only?
• 2. density- the density of air near Earths
  surface is greater than its density at high
  altitudes
• 3. pressure- air exerts a force called pressure

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Notes Quiz

• What is the most abundant gas in our atmosphere?
• 2. What are some trace gases that are in our
  atmosphere? (name 3)

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3. What is ozone?a) liquid oxygenb) oxygen
molecule with 3 atoms of oxygen instead of 2c) a
form of rust
4. What are some of the solid particles in air?
(Name 4)
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5. Why would there be more water vapor in a
tropical rain forest than in a desert?a) the
climate is wet in a rain forest and a lot of
water would evaporateb) there would be a lot of
transpiration from the treesc) both a and b
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• 6. What is air pressure?
• 7. In what 2 units is it measured?
• 8. How is air pressure affected by density?

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9. How is air pressure affected by
altitude?10. Does air have mass? How do you
know?