bonding

what is an ionic bond

an electrostatic connection between a metal and non metal

what is a covalent bond

attraction between non-metals that shares electrons

what is a metallic bond

attraction between two metals

what happens to metals and non metals in ionic bonding

metals lose electrons (becomes positive) and non metals gain electrons (becomes negative)

what happens in covalent

share electrons as there is not a metal to donate

what happens in metallic bonding

metals lose electrons (become positive) and as there are no non metals to accept the electrons they remain delocalised

what type of bonding is diamond and graphite

covalent

qualities of graphite

• high mp

• conducts electricity

• soft

• carbon forms 3 bonds

• has delocalised electrons

• has a giant structure

qualities of diamond

• high mp

• does not conduct electricity

• hard

• carbon forms 4 bonds

• all electrons in covalent bonds

• giant structure

why do diamond and graphite have high melting points

giant lattice structure: takes lots of energy to overcome the covalent bonds

why is diamond not an electrical conductor

diamond uses all of its electrons in covalent bonds so there are no delocalised electrons to form an electrical current

what is a graphene/nanotube

a single sheet of graphite with no intermolecular forces and is incredibly strong and conducts electricity (can be rolled into nanotubes)

what is a fullerene

a carbon atom with 3 covalent bonds but have a molecular formula. this means they have a lower melting point than graphite as only intermolecular forces need to be overcome. cannot conduct electricity even though they have delocalised electrons as the electrons can only move around one molecule

why are metals described as ductile and brittle

metals are strong and not brittle. when the metal is hit the layers are able to slide over each other. the metallic bonds do not break as the electrons are free to move

why are metals good conductors of electricity

the delocalised electrons are able to conduct thermal energy through the structure

what are alloys

a mixture of two or more metals