The word ‘carbon’ is derived from the Latin word ‘carbo’ meaning soot or charcoal. Carbon is found in free as well as in combined state. In the free state, it is found nature as diamond, graphite and coal. In the combined state, it is found in compounds like carbon dioxide of air, limestone, chalk etc.

Sources of carbon

• Carbon dioxide of air.
• Petroleum matter or natural gases.
• Minerals and rocks like limestones.
• Organic compounds like carbohydrate, protein and fat.

Nature of carbon

Carbon is a non-metal. It belongs to group IV A and period 2nd of the periodic table. Its atomic number is 6 and atomic weight is 12. Carbon is the first member of group IV A elements. These six electrons are arranged in different energy levels of a carbon atom as shown below.

Carbon has 4 valence electrons. It indicates that carbon can attain a stable configuration like that of inert gases in the following ways:

• By losing four valence electrons.
• By gaining four electrons in its valence shell.
• By sharing its four valence electrons with other atoms.

Physical properties of carbon

Allotropyis the different structural or physical modification of the same element but they have same chemical properties. The different forms of the same element are called allotropes. There are two allotropes of carbon which are given below, Graphite, diamonds and coals are nearly pure form of carbon

• Crystalline form: diamond and graphite.
• Amorphous form: coal, charcoal, animal charcoal, coke etc.