1. The element present in the largest amount in rocks and minerals is–
2. The metal that is present in Photo Films is–
3. Which of the following is in liquid form at room temperature ?
4. The property of a substance to absorb moisture from the air on exposure is called–
5. Which of the following elements is non-radioactive?
6. Brass gets discoloured in air due to the presence of which gas in air–
(a) Carbon dioxide
(c) Hydrogen Sulphide
7. The fastest acting enzyme in the biological kingdom is–
(d) carbonic anhydrase
8. Lightening cause rainfall because–
(a) It cause combination of oxygen and nitrogen
(b) Some of the gas molecules become bigger
(c) It activate H2O molecule
(d) Photo-electricity reaction starts
9. Polythene is industrially prepared by the polymerisation of–
10. Nitrification means–
(a) Liquifaction of nitrogen
(b) Convert the atmospheric nitrogen to effective nitrogen compound.
(c) Production of nitrogen from air
(d) Conversion of nitrogen to nitric acid.