1. Science 20

2. Quiz Fill in the blanks in the Following Diagram Sugar + _______________ + Energy CO2 (g) + __________ CO2 + _______________ Sugar (g) + __________ Which Organisms is associated with this equation?

3. The Oxygen Cycle Most living things cannot survive without a source of oxygen. Oxygen react so intensely with other elements in chemical reactions that significant amounts of energy are released This is not burned up because of photosynthesis.

4. Connections to the Carbon Cycle The sinks for carbon are the sources for oxygen and vice versa In both, the main processes responsible for the cycling through ecosystems and photosynthesis and cellular respiration Differences are that carbon dioxide comprises only about 0.03% of the atmosphere, whereas oxygen accounts for 21%

5. Human Impact Biggest human impact is the affects of the ozone layer A molecule comprised of three atoms of oxygen – O 3 Ozone forms when high-energy radiation from the sun breaks apart oxygen molecules and forms free oxygen atoms Free oxygen atom can then react with an unbroken oxygen molecule to form ozone

6. Human Impact The balance is upset through the upset through the release of pollutants such as CFC’s, that migrate to the ozone layer and cause more ozone to be broken down. The thinning layer is cause for concern because it shields Earth from the sun’s powerful ultraviolet radiation.

7. Impact of Wildfires Decomposers can break things down in years but a wildfire can accomplish the same thing in seconds. Wildfires are a powerful example of a number of oxidation reactions that rapidly release energy The major issue is when the soil is moved after rain because there is no vegetation to hold it in place. Minerals are exposed and chemically react with atmosphere oxygen.