Question

Write the types of allotropes of carbon. Give three examples of each.

Answer 1

Hint: An element can exist in more than one physical form. The chemical properties of different physical forms will be similar, but the physical properties will be different. The phenomenon, in which an element exists in different physical forms, is called allotropy. Different physical forms of the element are called allotropes or allotropic forms.

Complete answer:
Allotropes are formed by the elements showing variable valence and/or variable coordination number. Carbon atoms also show catenation. Catenation is the tendency of the element to form chains or rings by forming covalent bonds with itself. Due to variable oxidation state or variable coordination number and the catenation tendency, carbon exists in several allotropic forms.
Allotropes of carbon are different physical forms. In different allotropes of carbon, strong covalent bonds are present between carbon atoms. But allotropes have different properties as different arrangements of covalent bonds are present.
Carbon shows both crystalline and amorphous forms of allotropes.
Diamond, Graphite and Buckminsterfullerene are the crystalline allotropic forms of carbon.
Charcoal, coke and lampblack are amorphous allotropic forms of carbon.

Additional Information: Allotropes show different behaviour. For example, graphite shows good electrical conductivity whereas diamond shows poor electrical conductivity. Graphite has one loosely bound electron whereas in diamond, all the four electrons are tightly bound.

Note: Diamond is a very hard crystal. It is transparent in nature. The carbon atoms form a tetrahedral lattice. Diamond has poor electrical conductivity, but very good thermal conductivity.