It’s Elemental: Exploring Environmental Health through Chemistry Earth Cycles The MIDAS Project: Supported by the Science Education Partnership Award Program of the National Center for Research Resources, National Institutes of Health (Grant No. R25 RR018634)
Elements exist in different forms in and around the earth. Certain elements such as nitrogen (N2), carbon (C), and oxygen (O2) move through Earth in cycles.
These cycles are necessary to help balance and regulate Earth and its atmosphere.
Changes in these natural cycles can be caused by human activities. Let’s see how these changes can affect the environment.
The Water Cycle
The Water Cycle http://geosurvey.state.co.us/wateratlas/images/thumb_fig2_2.jpg
Water (H2O) can change states from solid to liquid to gas throughout its cycle. Water can even change straight from a solid to a gas. For review of states of matter lesson, see Atoms Notes. http://www.800mainstreet.com/1/0001-02-statesofmatter.html
Changes in one part of the water cycle can affect other parts of the cycle. When a dam is built or a forest is cut down water is diverted from its usual route.
Mansfield Dam, Austin Texas http://larae.net/photo/austin/
A dam reduces the amount of water moving down the river, and cutting down a forest can increase runoff and erosion as well as reducing the amount of water returning to the atmosphere from transpiration.
Transpiration animation • http://techalive.mtu.edu/meec/module01/Transpiration.htm
http://portal.unesco.org/education/en/ev.php-URL_ID=28912&URL_DO=DO_TOPIC&URL_SECTION=201.htmlhttp://portal.unesco.org/education/en/ev.php-URL_ID=28912&URL_DO=DO_TOPIC&URL_SECTION=201.html
This can actually change weather patterns. In addition, pollutants in our water can harm both people and other living things. http://www.popular-communications.com/hurricane%20copy.jpg
The Carbon Cycle http://i.treehugger.com/images/2007/5/24/timemagazine.jpg
http://www.kidsgeo.com/images/carbon-cycle.gif
All living things contain carbon (C). It is also found in water, air and soil. As part of the carbon cycle, carbon can move from the Earth’s layers to the atmosphere, the ocean, into living things and back to the soil.
hydram.epfl.ch/VICAIRE/ mod_2/chapt_3/text.htm
One form of carbon, carbondioxide (CO2) is found naturally as part of the atmosphere. Earth would be frozen without carbon dioxide and other gases.
http://www.combatclimatechange.ie/uploadedfiles/Climate_Change_Facts/greenhouse%20effect%20from%20safeclimate%20site.jpghttp://www.combatclimatechange.ie/uploadedfiles/Climate_Change_Facts/greenhouse%20effect%20from%20safeclimate%20site.jpg
Plants need carbon dioxide for photosynthesis. http://www.sinhhocvietnam.com/vn/modules/News/pic/1133729353_photosynthesis.gif
When fossilfuels or trees are burned, they release excess carbon dioxide into the atmosphere.http://fireupdate.com/images/6.jpg
Increased amounts of carbon dioxide are a cause for global warming and the changes in the Earth’s climate. http://www.cosmosmagazine.com/node/825
Carbon Cycle Map • http://www.windows2universe.org/earth/climate/carbon_cycle.html
The Nitrogen Cycle http://www.visionlearning.com/library/modules/mid98/Image/VLObject-2068-030815020825.jpg
Our atmosphere is made mostly of nitrogen. It is necessary for all living things to make amino acids into protein to become part of their tissues as they grow. http://www.kidsgeo.com/images/earths-atmosphere.jpg
Most organisms cannot use nitrogen gas (N2) as it is found in the atmosphere. It can only be used once it has been combined or “fixed” with other elements to form compounds like ammonia (NH3) and nitrate (NO3).
Nitrogen is made usable by lightning, or soil bacteria,(in nodules or free living) in a process called nitrogen fixation. http://www.insurevents.com/images/Lightning_strike.jpg
Animals get nitrogen from their food. Most plants get nitrogen from the soil or water.
Releasing Nitrogen back intothe Atmosphere • Denitrifying bacteria get energy from decay of plants and animals and convert Nitrogen compounds into Nitrogen gas that gets released back into the atmosphere
Some farmers use nitrogen- containing fertilizers to help plants grow larger and faster. The increased amounts of nitrogen can flow into rivers and streams as runoff. Dangers of too much Nitrogen
This causes aquatic plants and algae to grow more quickly, blocking sunlight and choking out fish and other animals. This causes aquatic plants and algae to grow more quickly, blocking sunlight and choking out fish and other animals.
. Exhaust from burning fossil fuels from vehicles and power plants put lots of Nitrogen into the air which combines with rain drops causing acid rain harming the organisms that live in water
It’s your planet! Please take care of it!
