Question 12
Non-metals are poor conductors of electricity. Which one is the exception?
The right answer is the one marked above.
Graphite — one of the allotropic forms of carbon. Although a non-metal, it is an electrical conductor.
Carbon supplies the exception to the density rule as well: non-metals have a relatively low density, but diamond — another form of carbon — has a high one. Diamond, unlike graphite, is an electrical insulator.