(i) A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance whereas Z is a good conductor of electricity. Identity X, Y, Z.
(ii) An element, X, on reaction with oxygen forms an oxide XO2. The oxide when dissolved in water turns blue litmus red. State whether element X is a metal or a non-metal.
(iii) Name the metal which is alloyed with copper to make bronze.