Question

31. The process of giving a coating of ________
to copper or brass is called tinning.
a) Zinc b) tin c) copper d) iron
32. _________ is used to make photographic film
a) Sodium chloride b) silver bromide
c) Potassium iodide d) Copper chloride.
33. ___________ is used in hydrogenation of vegetable oils
a) Chlorine b) Carbon
c) Hydrogen d) Nitrogen
34. Which of the following is called as noble metal?
a) Mercury b) Gold c) Lithium d) Caesium
35. Which of the following is a non-metal but is lustrous?
a) Carbon b) Mercury c) Iodine d) fluorine
36. Iron, cobalt and nickel are metals which are
a) Non-magnetic b) magnetic
c) Insulator d) none of them
37. Identify X in the given equation of aerobic respiration.

a) Water b) Oxygen
c) Ethyl alcohol d) Nitrogen
38. The following word equation shows a chemical process that take place in an organism Y. What is organism Y?


a) Algae b) Protozoan
c) yeast d) Hydra
39.In which organisms does photosynthesis happen?
a) Plants b) Animals
c) Plants and animals d) None of the above
40. Which of the following need oxygen to survive?
a) Plants b) Animals
c) Plants and animals d) None of the above​

Answer 1

Answer:

31.iron

32.silver brimode

33.nitrogen

34.mercury

35.iodine

36.insulator

37.oxygen

38.yeast

39.plants and animal

40.plants and animal