Giant Covalent Structures

Describe the structure of Giant covalent structures

Substances that consist of giant covalent structures are solids with very high melting and boiling points, requiring lots of energy to break covalent bonds between the atoms. All the atoms,in these structures are linked to other atoms by strong covalent bonds.

What are the three examples of Giant Covalent Structures

-Dimond

-Graphite

-Silicon dioxide

Why cant giant covalent substances conduct electricity

They don’t contain charged particles, so they don’t conduct electricity even when molten except graphite

Why are Dimonds hard and have a high melting and boiling point?

Dimond has a giant covalent structure made up of carbon atoms that each form four covalent bonds.

-These strong covalent bonds take a lot of energy to break and give Dimond a very high melting point.

Why can’t Dimond conduct electricity

As all of the outer electrons are in covalent bonds so has no free electrons to carry an electric charge

Describe the structure of silicon dixode(silica)

-Contains silicon and oxygen which are covalenelty bonded together.

-Contains a huge number of covalent bonds which is why it has a high melting and boiling point since a great deal of energy is needs to break bonds.

Describe the structure of Graphite

-Each carbon atom only forms three covalent bonds creating sheets of carbon atoms arranged in hexagonal rings so rings of 6 carbon atoms.

What are the properties of Graphite

-Soft and slippery

-Has a very high melting and boiling point

-Good conductor of electricity and heat

Why is Graphite soft and slippery

The hexagonal rings of carbon atoms are arranged in layers and there are no covalent bonds between the layers-they’re held together weakly. This means they’re free to move over each other. Making them soft and slippery so ideal as a lubricating material to reduce friction

Why does graphite have have a high melting and boiling point

As the covalent bonds require great deal of energy to break them

Why can graphite conduct electricity and thermal energy

-Eacg carbon atom forms covalent bonds to three other carbon atoms. So each carbon atom has one electrons that is not in a covalent bond.These electrons are released from the carbon atom which is called delocalised electrons. These electrons can move and conduct electricity and heat

What is Graphene

A single layer of graphite joined together in hexagons.

-The sheet is just one atom thick making it a two dimensional substance

What are the properties of Graphene

-Good conductor of electricity as it has delocalised electrons which can move through the graphene and carry a charge.

-Extremely strong and high melting and boiling point beacsue it has a large number of strong covalent bonds which require great deal of energy to break

-Very light so can be added to composite materials to improve their strength without adding much weight

What can graphene be useful for in the future

Useful for electronics