The Atmosphere Chapter 15 section 1 Characteristics of the Atmosphere S6E3b –Relate various atmosphere conditions to stages of the water cycle.
Does air have mass? Explain your answer
The Atmosphere The atmosphere is a mixture of gases that surrounds Earth and held in place by gravity. Contains oxygen to breathe Protects us from the suns’ damaging rays
Composition of the Atmosphere Copy picture 1%: Argon Carbon dioxide Neon Helium Methane Krypton Hydrogen
Bell Ringer: Feb. 10th Compare cleavage and fracture.
Composition of the Atmosphere Most common gas is nitrogen Oxygen is 2nd most common Small particles: dust, volcanic ash, sea salt, dirt, and smoke Water – liquid water (water droplets) solid water (snow and ice crystals), water vapor (gas) Stop: demonstration
Characteristics of the Atmosphere Atmospheric Pressure Atmosphere is held around the Earth by gravity. As gas molecules are pulled by gravity it causes air pressure. Air pressure is the measure of the force with which air molecules push on a surface. At sea level, there is 15 lbs of pressure per square inch. Air pressure is the strongest at Earth’s surface because most gas molecules are pushing down on you. As altitude increases, air pressure decreases. As altitude decreases, density increases.
Stop and Think When you let go of a helium balloon outside, why does it float away going further and further up? Because helium is lighter than oxygen in the air (less dense) Why does a hot air balloon float? Because hot air rises (b/c it’s less dense) Why can’t helicopters fly in the upper atmosphere? There is not enough air molecules to help the helicopter move the propellers around in a circular motion. The higher the atmosphere, the less dense the air.
Changes in Temperature As altitude increases there is a change in the temperature. Temperature varies as a result from the way solar energy is absorbed by gases
Layers of the Atmosphere Include information on your foldable. Pages 450-453 in textbook Name of Layer Altitude range Temperature range Other features