B:) Allotropes of carbon
- Two or more different physical form of an element can exist is known as allotropes.
- Carbon has three major allotropes
- Allotropes have same chemical properties but different physical properties.
|each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure.||each carbon atom is bonded to three other carbon atoms in the same plane giving a hexagonal array.||Each carbon atoms connected by single and double bonds so as to form a closed mesh, with fused rings of five to seven atoms to form a football like structure.|
|High melting point||Low melting point||High melting point|
|Hard in nature||soft, slippery||Lubricating material|
|Strong Vander wall forces||Have weak Vander wall forces.||Have weak Vander wall forces.|
|insoluble in water and organic solvents||insoluble in water and organic solvents||insoluble in water and organic solvents|
|Bad conductor of electricity||Good conductor of electricity||Able to conduct electricity|
|Chemical formula- C||Chemical formula- C||Chemical formula- C60|
Note-fullerene named after Buck minster Fuller and used as radical scavenger and antioxidant.
IMPORTANT PROPERTIES OF CARBON
- Catenation- catenation is the bonding of atoms of the same element into a series, called a chain or a ring shape.
- Catenation occurs most readily with carbon, which forms covalent bonds with other carbon atoms to form longer chains and structures.
- Tetravalency- carbon has a valency of four due to which it is known as tetravalent.