Download Composition of the Atmosphere - Holy Family School | Phoenixville

Composition of the Atmosphere
Weather
• Weather- the condition of Earth’s atmosphere
at a particular time and place
• Atmosphere- the later of gases that surround
the planet
The atmosphere makes conditions
suitable for living things
• It contains oxygen and other gases living
things need to live
• It keeps Earth’s surface warm enough for
water to exist as a liquid
• Protects living things from radiation from the
sun
• Prevents the surface from being hit by most
meteoroids
Composition of the Atmosphere
Nitrogen
•
•
•
•
•
Most abundant gas in the atmosphere
Is essential to living things
Is found in proteins
Is needed for growth and repair of cells
Most living things cannot obtain nitrogen
directly from the air
Oxygen
• Second most abundant
gas in the atmosphere
• Plants and animals take
it directly from the air
• Is needed to release
energy from food
• Is needed for fuels to
burn
• It forms ozone when it
interacts with lightning
Carbon Dioxide
• Is essential to life
• Plants must have
Carbon Dioxide to
produce food
• Animals give carbon
dioxide off as a waste
product
• Burning fuels release
carbon dioxide
Other Gases
• Oxygen and nitrogen make up 99% of dry air
• Carbon Dioxide and argon make up most of
the other 1%
• The remaining gases are called trace gases
because only small amounts of them are
present
Water Vapor
In reality, air is not dry because it contains water
vapor
• Water vapor- water in the form of a gas
• It is invisible and is not the same as steam
Water Vapor Cont.
• The amount of water vapor in
the air varies from place to place
• It plays an important role in the
weather
– Clouds form when water vapor
condenses out of the air to form
tiny droplets of liquid water or
crystals of ice. The droplets or
crystals fall as rain or snow if they
become large enough.
Particles
• Air contains tiny solid and liquid particles of
dust, smoke, salt, and other chemicals