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Human health risks due to exposure to chemicals include inorganic chemicals,
some of which are potential toxic substances.
1.6 Organic Chemistry
Carbon is one of the most copious elements in our world and it is part of all living
organisms.
Covalent compounds containing predominantly carbon as well as hydrogen are
called organic compounds. Comparisons of organic and inorganic compounds are
given in Table 1.3.
Carbon has six electrons distributed with two electrons on the small orbit closest
to the nucleus, and the four electrons in the orbit further away (Fig. 1.16). The outer
orbit has enough space for up to eight electrons. Hence, carbon will bond up to four
times with other atoms, until it reaches eight electrons in its outer ring.
Carbon’s ability to form four bonds (Fig. 1.17) gives it a remarkable amount of
flexibility. It can exist in a simple state, such as carbon dioxide, in long chains such
as proteins, in ring structures such as sugar, as well as numerous other complex
structures.
There are several general differences between the chemistries of organic compounds and inorganic compounds, which will help give an overall view of organic
chemistry.
Carbon atoms have the capability to bond to another carbon atom and form longer chains.
Hydrogen
Hydrogen
Hydrogen
Hydrogen
Carbon
Fig. 1.17 Arrangement of
atoms in methane
1.6 Organic Chemistry