Bonding, Structude and Properties of Matter Flashcards
What are polymers?
Large molecules formed from many small molecules called monomers.
What is an alloy?
A mixture of a metal element with at least one other element, usually another metal.
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Why is steel alloy much stronger than iron on its own?
Steel is a mixture of carbon and iron. The carbon atoms distort the regular lattice structure, meaning a greater force is required for the layers to slide over one another, making it harder.
What are fullerenes?
Hollow molecules of carbon.
What are carbon nanotubes?
Cylindrical fullerenes.
Why can fullerenes conduct electricity?
They contain delocalised electrons which can move through their structures.
What are potential uses of fullerenes?
Drug delivery
Anti-oxidants
Catalysts
Why is a mixture of carbon nanotubes and plastic used in wind turbine blades rather than plastic alone?
Carbon nanotubes are very strong and stiff. They can be used to reinforce the plastic as a composite material instead of carbon fibres. Composite materials are strong and flexible.
Why are metals good conductors of thermal energy?
When a metal is heated, energy is transferred to delocalised electrons. Theses are free to move through the structure of the metal transferring energy to atoms and other electrons.
Why do metals have high melting points?
Metals in the solid state have giant structures of atoms held together by metallic bonding. A lot of energy must be transferred to overcome this strong bonding.
Compare diamond and graphite.
- Both contain covalent bonds.
- Diamond contains 4 atoms bonded to each carbon atom whilst graphite has 3.
- Graphite contains hexagonal rings of layers.
- Graphite has weak forces between layers.
- Graphite contains delocalised electrons.
Why does diamond have a very high melting point?
Its structure contains very many strong covalent bonds. A lot of energy is needed to break these bonds.
Why is graphite slippery?
There are only weak intermolecular forces between the layers of atoms in graphite which allow the layers to slide over each other easily.
Why is graphite very hard?
It has a giant covalent structure and its many strong covalent bonds resist forces that could distort the structure.
