Carbon C
Atomic Number: 6
Atomic Weight: 12.01
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Human Physiology:

- Key element of life; present in all organic and to a lesser extent inorganic compounds

- Only element capable of forming long chains and rings that are the structural framework for
living cells, e.g. DNA

Prevalence:

- Present everywhere in the earth's biosphere: dissolved in the atmosphere as carbon dioxide
(CO2), present in fossil fuels as hydrocarbons, found as graphite (one of the softest know
metals) and as diamonds (the hardest naturally occurring substances)

Source:

- Present in most of our food supply
- From increased fossil fuel burning globally

Toxicity:

- Some carbon compounds are highly toxic, e.g. carbon monoxide gas (CO), cyanide

- Carbon black exposure can lead to lung and heart damage