Bonding and electrcial conductivty

This video covers the electrical conductivity of substances with different bonding (covalent, ionic and metallic).

[공부좀하자-ff]

Sir, may I ask if you meant "localised electrons" instead of "delocalised electrons" at 4:24 ?

[cooldudenezo]

Sir, I don't understand how graphite is a good conductor because it has delocalised electrons, but then molecules with delocalised electrons are poor conductors?