Allotropes of carbon

Question 1

\What is diamond and mention its properties

Answer 1

• giant covalent structure made up of each carbon atom forming 4 covalent bonds.
• hard and those strong covalent bonds take a lot of energy to break and give diamond a very high melting point and does not conduct electricity because it has no free electrons or ions.

Question 2

What is graphite and mention its properties

Answer 2

• giant covalent structure made up of each carbon atom forming 3 covalent bonds creating sheets of carbon atoms is hexagons
• No CB between layers so they are held weakly so they slide over each other = graphite is soft and slippery which is ideal for lubricant materials
• High mp - CB in the layer need loads of energy to break also 3/4 electrons used in bonds, delocalised electron is free to move and graphite then conducts electricity and thermal energy (heat)

Question 3

What is graphine and mention its properties

Answer 3

• A single layer of graphite - a sheet of carbon atoms together in hexagons. The sheet is one atom thick - two dimensional substance.
• The network of covalent bonds make it really strong and light so can be added to composite material to improve strength without adding much weight.
• contains delocalised electrons so can conduct electricity through the whole structure = potential for use in electronics

Question 4

What is fullerenes and mention its properties

Answer 4

• molecules of carbon shaped like closed tubes or hollow balls, but mainly made up of carbon atoms arranged in hexagons but can also contain pentagons or heptagons.
• Fullerenes can be used to cage other molecules like drugs to help deliver them to certain part of body.
• High SA: V - could be used to make industrial catalysts - individual catalysts molecule could be attached to fullerene and they also make good lubricants.

Question 5

Use of nanotubes

Answer 5

• can form nanotubes
• Ratio of length : diameter is high - used in electronics or add strengthen materials w/o adding much weight - tennis racket frame
• nanotubes can conduct both electricity and thermal energy
• High tensile strength ( not broken when stretched )
  -Technology that use very small particles such as nanotubes = nanotechnology