Carbon and its Compounds – Notes
Forms of Carbon
Carbon is the sixth most abundant element in the universe.
In the free state, carbon occurs as diamond, graphite, fullerene and coal.
In the combined state, carbon can be in the form of carbon dioxide, carbon monoxide, petroleum, vegetable oils, lime stone, magnetite, dolomite and calamine.
Allotropy is the property of an element that allows it to exist in more than one form.
Diamond, graphite and fullerenes are crystalline allotropes.
Coal, coke, wood charcoal, lampblack, gas carbon, petroleum coke and sugar charcoal are the amorphous allotropes of carbon.
A diamond is a rigid, compact, three dimensional structure and is hard to break. It is a bad conductor of heat and electricity.
Graphite contains carbon atoms in hexagonal rings. It has a two dimensional layer structure.