question_answer 74)

    A non-metal X exists in two different forms Y and Z. Y is hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.

Answer:

                  A non-metal X is carbon (C). Carbon exists in two different forms called the allotropes of carbon. These allotropes are diamond and graphite. Y is diamond because diamond is the hardest natural substance. Z is graphite which is good conductor of electricity.