The hardest substance available on earth is

A. Platinum

B. Quartz

C. gold

D. Diamond

You can do it
  1. The metallic constituents of hard water are
  2. Which of the following is in liquid form at room temperature ?
  3. Epoxy resins is used as
  4. The location and energy of an electron in an atom can be specified by
  5. Quartz crystals normally used in quartz clocks etc. is chemically
  6. The oxide of Nitrogen used in medicine as anaesthetic is
  7. According to Daltons atomic theory the smallest particle which can exist independently is
  8. Permanent hardness of water can be removed by adding
  9. Which of the following elements is a metal
  10. Which of the following is the lightest metal ?
  11. The fastest acting enzyme in the biological kingdom is
  12. Which of the following parts of the sun is easily visible only during a total solar eclipse?
  13. The most important ore of Aluminium is
  14. The metal used in storage batteries
  15. The element present in the largest amount in rocks and minerals is
  16. Which of the following elements is obtained from sea weeds ?
  17. The recent atomic weight scale is based on
  18. Brass gets discoloured in air due to the presence of which gas in air
  19. Glass is made from the mixture of
  20. Earth's seasons are caused by which of the following?
  21. The colour of Emerald is
  22. The hardest substance available on earth is
  23. When a gas is turned into a liquid, the process is called
  24. Apparatus invented by Archimedes is :
  25. What is the unit for measuring the pitch or frequency of sound ?
  26. Carbon tetrachloride fire extinguisher should not be used in closed room because it produces poisonous…
  27. The fastest-running terrestrial animal is
  28. The removal of top soil by water or wind is called
  29. Which of the following characters is not shown by hydrogen
  30. Pollination by birds is called