Why Is Carbon Important to Life?
- The chemical symbol for carbon is the capital letter, C. The atomic number for carbon is six. Its atomic weight is 12.11. Usually carbon is found in combination with other elements as in carbon dioxide, limestone, coal, and petroleum. Less than one percent (0.32%) of the earth's atmosphere and 0.2% of the earth's crust are carbon.
- Pure carbon only exists in three forms: diamonds, graphite, and carbon black (charcoal, for example). However, 18% of all living things on earth is comprised of carbon. That includes human beings, plants, and animals. Like all animals, humans have a metabolic need for carbon. We get it by eating carbohydrates which are produced in plants during photosynthesis, when carbon dioxide combines with water. Because carbon is so intrinsic to all forms of life, the study of organic carbon compounds is a primary emphasis of organic chemistry.
- The carbon cycle is a sequence of events that transfer carbon dioxide from the atmosphere to the soil so plants can absorb and use it. Henrik Lundegardh, the Swedish plant physiologist who is credited with explaining the carbon cycle in the 1920s, was one of the first to measure the carbon dioxide in the atmosphere. He discovered that carbon dioxide escapes from the soil when organic matter like manure and dead plants decays. It also enters the atmosphere when animals exhale. Rain, soil bacteria acting on decaying organic matter, and manure add carbon dioxide to the soil. Plants need carbon dioxide to produce healthy green leaves.
- Too much carbon dioxide in the atmosphere may be the cause of global warming because carbon dioxide and methane gas absorb the heat from the sun, which produces the "greenhouse effect." (Methane gas is another carbon byproduct which is released from sewers, swamps, and other marshy areas.) Because the use of fossil fuels like coal and petroleum releases carbon dioxide into the atmosphere, many environmentalists are concerned that the continuing use of these fuels causes global warming. Other scientists believe that the rise in the temperature of the oceans is a larger causative factor of global warming. Nevertheless, if nations reduce their reliance on fossil fuels, less carbon dioxide will be released into our atmosphere.
- Carbon has quite a few industrial uses as well. First and foremost, carbon is the key ingredient in fossil fuels. Carbon in filters absorbs impurities. It is found in carbon paper, paint, and ink. Carbon, added to tires, helps them to wear evenly so they last longer. Finally, by measuring the ratio of carbon to nitrogen and by measuring the amount of carbon-14 that remains in a piece of organic material such as a fossil or a piece of wood, scientists can get a good idea of the age of an item.