Grade 7 heat unit review

1. Things you need to know for
your test
Monday April 29th, 2013
Mark it in your calendars if you
haven’t already done so!

2. The Atmosphere
• Definition – blanket of gases and other
particles that surrounds Earth.
• Within the atmosphere, we breathe in a
mixture of gas (oxygen) and dust of
various substances. Our lungs filter
the elements we don’t want and pump
the oxygen to our organs

3. The layers of the atmosphere
• Troposphere – 0 to 20 km
• Stratosphere – 20 to 50 km
• Mesosphere 50 to 85 km
• Thermosphere – 85 to 690 km
• Exosphere 690 to 10,000 km
• Terrible Super Mario Tames Elephants

4. In one sentence, - What do they
do?
• Troposphere - all the weather takes place in
this region.
• Stratosphere – ozone layer, protects us from
Ultra Violet rays.a
• Mesosphere – Burns and incinerates any debris
from space, protects us from meteors!
• Thermosphere – where the space station orbits.
• Exosphere – Where the satellite orbits. Satellite
TV and Radio!

5. Statistics to know
• 20% of the Sun’s energy is absorbed in the
atmosphere by dust, water vapour, and water
droplets.
• 30% of the energy from the sun is reflected
back out to space by the atmosphere.
• 46% of the Sun’s energy is absorbed by the
Earth’s water and land surfaces
• 4% of the Sun’s energy is reflected by Earth’s
water and land surfaces

6. Greenhouse Gases
• Carbon Dioxide – Cars, what we breathe
out.
• Methane – natural gases, fuels.
• Nitrous Oxide – laughing gas, anesthetics
• Halocarbons – Human made pollution
• Ozone – Earth’s Atmosphere
• Water vapour – self explanatory?