Allotropes Flashcards
What are Allotropes?
Structurally different forms of an element (carbon)
What is special about each Allotrope?
Arranged differently, have different physical and chemical properties.
What are the Allotropes of Carbon?
Graphite, diamond, fullerenes, carbon nano-tubes and graphene.
What are the properties of diamond?
- Does not conduct electricity
- Lustrous
- Colourless and clear
- Hard
- High melting point
- Insoluble in water
What are the uses of diamond?
Jewellery - when cut by experts, it will sparkle and reflect light in an attractive way.
What is Diamonds hardness and high melting point?
- Diamonds are useful for cutting tools - diamond tipped discs
- Heavy duty drill bits - drill through rocks in the oil edploration industry
- They stay sharper
What is the structure and bonding of diamond?
- Giant molecular structure
- Each carbon is covalent bonded to 4 other carbon molecules
- Covalent bonds are strong
- Diamond contain a lot of covalent bonds
What is important about the diamond allotrope?
No free electrons so it can’t conduct electricity. (Not in solid or liquid form).
What are the properties of graphite?
- An electrical conductor
- Lustrous
- High melting point
- Insoluble in water
- Black and opaque
- Slippery
What are the uses of graphite?
- Pencils
- Component of many lubricants
What is structure and bonding?
- Giant molecular structure - a lot of energy needed to separate atoms
- Very high melting/boiling point
- Carbon atom each covantly bonded to 3 other carbon
- Contains layers of carbon atoms
- Slide over each other easily
For graphite, what are the sheets of carbon arranged in?
Hexagons
How many covalent bonds does each carbon atom form in graphite?
Three
What makes graphite soft and slippery?
There are no covalent bonds between the layers meaning they are held together very weakly making them free to move over each other.
Why does graphite have an high boiling point?
It has ahigh boiling point and needs a lot of energy to break the covalent bonds.
How does graphite conduct electricity?
each carbon atom is covalently bonded three times however one delocalised electron from each carbon atoms remains free. This means it is able to move freely and carry a charge.
What is graphene?
It is one layer of graphite and is a sheet of carbon atoms which are joined together in hexagons.
Graphene is one atom thick, what type of compound does this make it?
Two dimensional compound
How is graphene strong?
It has a network of compounds
What advantage does graphen being light have?
It can be added to composite materials to improve there strengths and because graphene is light not much weight would be added on to the overall material.
Graphene has delocalised electrons so it can conduct electricity what potentially could graphene then be used for?
Electronics
What is a fullerene?
A molecule of carbon and it is shaped like a closed tube or hollow ball.
What shoaes can fullerenes be arranged in?
Hexagons, heptagons or pentagons
Whay can fullerenes be used to ‘cage’ molecules?
It has a structure which can form around another atom or molecule, trapping them inside.
