1. By Melissa

2. What is the atmosphere? The atmosphere is the mixture of gases that surround Earth. The atmosphere is 78% nitrogen, 21% oxygen, and 1% other gases. The atmosphere blocks harmful ultraviolet rays and regulates the temperature on Earth.

3. What Cycles Occur in the Atmosphere? Water Cycle: Precipitation Evaporation Condensation(clouds form) Transpiration Condensation Runoff

4. Carbon Dioxide Dead organisms CO 2 in the Atmosphere Combustion Destruction of Vegetation Photosynthesis Respiration Runoff Carbonification Decay

5. Are there any layers? There are 5 layers( from the outermost layer in): The exosphere, the thermosphere, the mesosphere, the stratosphere, and the troposphere. The exosphere extends into space. It is 400+ kilometers thick. Temperatures in the thermosphere range from about -112°F on the inside to about 2,000°F on the outside. This is where space shuttles orbit. This is also where the Northern lights are seen. It is 50-400 km thick. The air is very thin in the mesosphere. This is where meteors ( shooting stars.) are seen. It is 30-50 km thick. Ozone is in the stratosphere. Ozone protects us against harmful UV rays from the sun. It is 10-30 km thick. Weather occurs in the troposphere. The higher in the troposphere you go, the the lower the temperature and the thinner the air. It is 0-10 km thick.

6. How do Humans Impact the Atmosphere? How Can We Change This Impact? We impact the atmosphere by burning fossil fuels such as coal. It causes smog ( smoke + fog) and acid rain. We can reduce air pollution by: Using gas for barbeques instead of wood or coal Biking or walking to school instead of driving Recycling!

7. Credits "Air pollution." KIDCYBER. N.p., n.d. Web. 13 Feb. 2013.. "Earth Observatory." Earth Observatory NASA. N.p., n.d. Web. 3 Apr. 2013.. "Earth's Atmosphere." Windows to the Universe. N.p., n.d. Web. 28 Jan. 2013.. "Lecture 22: Ecosystem Structure and Function." Science. N.p., n.d. Web. 3 Apr. 2013.. "Oxygen Increases in the Atmosphere." Lunar and Planetary Institute (LPI). N.p., n.d. Web. 3 Apr. 2013.. "Watercycle." Enchanted Learning. N.p., n.d. Web. 3 Apr. 2013.. “Atmosphere: Layers of the Earth's Atmosphere | FactMonster.com." Fact Monster: Online Almanac, Dictionary, Encyclopedia, and Homework Help | FactMonster.com. N.p., n.d. Web. 6 Mar. 2013.