(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) A 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.
