Name the following :
(a) The hardest naturally occurring substance.
(b) A greyish black non-metal that is a good conductor of electricity.
(c) The third crystalline form of carbon.
Name
(a) a soft metal.
(b) a metal which is brittle.
(c) a non-metal which is lustrous.
(d) a liquid metal.
(e) a metal which is a poor conductor of electricity.
(f) a non-metal which is a good conductor of electricity.
(g) a liquid non-metal.
(h) the hardest naturally occurring substance.
(i) an inert gas.
Which of the following is hardest naturally occurring substance?