allotropes of carbon

what are allotropes?

different structural forms of a particular element

what structure is diamond?

giant covalent lattice

what are properties of diamond?

• insoluble

• high melting/boiling point

• hard

• useful as a cutting tool

• does not conduct electricity

why does diamond not conduct electricity?

• each carbon atom forms 4 bonds

• no free electrons to move through the structure and carry a charge

what structure is graphite?

giant covalent lattice

what are the properties of graphite?

• brittle

• good lubricant

• high melting/boiling point

• conductor

• soft

• weak forces of attraction between layers

why is graphite soft, a good lubricant, and brittle?

• weak forces of attraction between graphene sheets

• can slide over each other

why are graphite and graphene able to conduct electricity?

• each carbon atom forms 3 bonds

• there is a delocalised electron that can carry a charge through the structure

what structure is graphene?

simple covalent structure

what are properties of graphene?

• light

• conductor (delocalised electrons can conduct electricity through the whole structure)

• can be a sheet or rolled up into a tube

• one layer of graphite

what structure are fullerenes?

simple covalent structures - they are simple molecules

what are the properties of fullerenes?

• low melting points

  • due to weak intermolecular forces

• soft

• slippery

  • ball structures roll over each other

• good lubricants

• insulator

do fullerenes conduct electricity?

• no - they are insulators

• even though there is one free electron per carbon atom, the electron cannot move between molecules

what can fullerenes be used in?

• medicine

• as catalysts

• lubricants

• strengthening materials