The hardest substance available on earth is

A. Platinum

B. Quartz

C. gold

D. Diamond

Please do not use chat terms. Example: avoid using "grt" instead of "great".

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  1. The marine animal called dugong which is vulnerable to extinction is a/an
  2. The location and energy of an electron in an atom can be specified by
  3. The Panda belongs to the same family as that of
  4. The solar eclipse occurs when
  5. The metal that is present in Photo Films is
  6. Earth's seasons are caused by which of the following?
  7. The smallest functional and structural unit of kidney is called as
  8. Lightening cause rainfall because
  9. The speed of light with the rise in the temperature of the medium
  10. Apparatus invented by Archimedes is :
  11. The colour of Emerald is
  12. The intencity of Earthquakes is measured on
  13. Carbon tetrachloride fire extinguisher should not be used in closed room because it produces poisonous…
  14. Which of the following is in liquid form at room temperature ?
  15. Bromine is
  16. Quartz crystals normally used in quartz clocks etc. is chemically
  17. Which of the following elements is a metal
  18. Which of the following items will be attracted to the north pole of a permanent magnet by a magnet force?
  19. Brass gets discoloured in air due to the presence of which gas in air
  20. One fathom is equal to
  21. The oxide of Nitrogen used in medicine as anaesthetic is
  22. The formula of Plaster of Paris is
  23. Liquefied Petroleum gas (LPG) consists of mainly
  24. Polythene is industrially prepared by the polymerisation of
  25. Old-written material, which cannot be read easily can be read by
  26. What is the unit for measuring the pitch or frequency of sound ?
  27. Water has maximum density at
  28. Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of
  29. Cell membrane is
  30. The property of a substance to absorb moisture from the air on exposure is called