Flashcards in Structure And Property Deck (16):
why are ionic compounds so strongly bonded?
strong forces between oppositely charged ions.
why do ionic compounds have high boiling points?
because the bonding is so strong and requires a lot of energy to break up the giant ionic lattice.
why can ionic compounds conduct electricity when in the form of a liquid?
because it has free ions.
many covalent bonds have what boiling points?
low boiling points.
why do covalent bonds have low boiling points
because they have weak intermolecular forces.
many covalent bonds have no overall charge , what would this mean?
this would mean it can't carry electrical charge.
what are the properties of giant covalent structures?
- Very hard
- High melting points
- insoluble in water
why is graphite slippery?
because it's made in layers of giant covalent structures with weak intermolecular attraction between them.
graphite has delocalised electrons, what does this mean?
it can carry an electrical charge.
large carbon molecules built up of hexagonal rings are known as
fullerenes can have molecules placed inside of them, what does this allow for?
delivery of drugs to specific parts of the body.
why are pure metals malleable?
the layers of metals are able to slide over eachother.
alloys are usually mixtures of metals, how does this affect the strength of the material?
it will be stronger as the layers aren't able to slide over eachother as easily as they have different sized atoms in the layers.
the positive ions in metals allows for what?
a sea of delocalised electrons, this can then carry an electrical charge.
shape memory alloys do what when heated?
return to their original shape.