CHEMICALS IN THE ENVIRONMENT. CHEMICALS CYCLE Earth is a closed system – which means that all atoms on earth remain on earth, including carbon and nitrogen.
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CHEMICALS CYCLE
Earth is a closed system – which means that all atoms on earth remain on earth, including carbon and nitrogen.
As organisms grow and eventually die, they use and release certain elements.
These elements are continuously recycled within the environment.
CHEMICALS CYCLE - Carbon
Carbon is the “backbone” of life. Molecules existing as Carbon chains,
such as starches, sugars, proteins, and other compounds make up life as we know it.
Carbon exists in several forms on earth. By understanding the Carbon Cycle, we can understand the importance of carbon.
USES OF CHEMICALS carbon →limestone
Limestone (CaCO3: Calcium Carbonate) is a sedimentary rock composed of the remains of sea organisms such as coral and the shells of mollusks
Has great benefits in agriculture - neutralizing agent for soil and water.
Used as a building material Used by organisms to create essential compounds
such as sugars and proteins Used as a raw material in the production of
cement, glass and iron.
USES OF CHEMICALS carbon → carbon dioxide
Essential in photosynthesis
6H2O + 6CO2 ----------> C6H12O6+ 6O2 Used as a refrigerant – Dry Ice Used in fire extinguishers Beverage Carbonation Too much carbon dioxide in the atmosphere, some
believe, is causing global warming
USES OF CHEMICALS carbon → carbonic acid
Carbonic acid is produced when carbon dioxide reacts with water
CO2(gas)+H2O <---> H2CO3 Carbonic acid has been
a factor in the problems associated with acid rain
CHEMICALS CYCLE - Nitrogen
Nitrogen is essential to life as well – it is used to produce proteins and nucleic acids (DNA).
Nitrogen makes up 78% of the earth’s atmosphere, however most organisms are unable to utilize Nitrogen while it is in the atmosphere.
NITROGEN FIXATION
In order to be used by plants, nitrogen must first be converted to a useable form - this is called Nitrogen Fixation
Nitrogen can be “fixed”, or made useable, in several ways1. Biological Fixation - Nitrogen fixing bacteria exist in
the soil and are able to capture Nitrogen from the air and convert it into a form that plants may use.
2. Atmospheric Fixation - Lightning can convert atmospheric nitrogen to a useable form
3. Industrial Fixation - man-made processes can convert nitrogen to useable forms.
CHEMICALS CYCLE - Nitrogen
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PROBLEMS WITH NITROGEN
Too much Nitrogen in the environment can be hazardous.
Humans impact the amount of nitrogen by adding fertilizers, and generating industrial emissions.
Too much Nitrogen leads to eutrophication of lakes, acid rain, and health hazards especially to infants.
EUTROPHICATION
Too much Nitrogen (and Phosphorus) builds up in a body of water
This is usually due to runoff of fertilizers and other nitrogen products
The excess Nitrogen promotes algae growth - algal bloom
Bacteria feed on the dead algae. This activity depletes the lake of oxygen which is harmful to life in that body of water.
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