Quartz crystals normally used in quartz clocks etc. is chemically

A. A mixture of B and C

B. Silicon dioxide

C. Germenium dioxide

D. Sodium Silicate

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  1. The chemial name of Uria is
  2. Water has maximum density at
  3. Nitrification means
  4. Carbon tetrachloride fire extinguisher should not be used in closed room because it produces poisonous…
  5. Old-written material, which cannot be read easily can be read by
  6. In an atomic nucleus, neutrons and protons are held together by
  7. Which of the following characters is not shown by hydrogen
  8. Which of the following parts of the sun is easily visible only during a total solar eclipse?
  9. The intencity of Earthquakes is measured on
  10. Which of the following is commonly called a polyamide ?
  11. One fathom is equal to
  12. The metal that is present in Photo Films is
  13. Earth's seasons are caused by which of the following?
  14. Cell membrane is
  15. Permanent hardness of water can be removed by adding
  16. Rust is
  17. Which of the following elements is non-radioactive?
  18. The property of a substance to absorb moisture from the air on exposure is called
  19. Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of
  20. The fastest-running terrestrial animal is
  21. What is the unit for measuring the pitch or frequency of sound ?
  22. Which of the following is in liquid form at room temperature ?
  23. Which of the following elements is a metal
  24. The Panda belongs to the same family as that of
  25. The fastest acting enzyme in the biological kingdom is
  26. Apparatus invented by Archimedes is :
  27. The metal used in storage batteries
  28. Which of the following is the lightest metal ?
  29. The formula of Plaster of Paris is
  30. The metallic constituents of hard water are