Structure and Bonding Flashcards
what is an ionic bond
a bond between a non metal and a metal
why do ionic substances have high melting points
because they have strong electro static attraction
when do ionic substances conduct
when they are melted or dissolved
why do covalent substances have low boiling points
because they have low intermolecular force
why do covalent substances not conduct
they have no charged particles
name three giant covalent structures
- graphite
- diamond
- sand
why do giant covalent structures have very high melting points
there are lots of strong covalent bonds to break
why is graphite weak
because layers can slide over one another
why is diamond very strong
it is a rigid 3D network of bonds
why are melting points high in most metals
because there is strong attraction between the positive metal ions and the outer shell electrons
why do metals conduct
because delocalised electrons are free to move and carry current
name 5 properties of metals
- hard
- shiny
- silver coloured
- malleable (can be shaped)
- ductile (can be made into wires)
what are polymers
large structures made by joining many smaller monomers into chains
what are the two types of polymer
- thermosoftening
- thermosetting
what are thermosoftening polymers
polymers that can be softened by heat
