41. Which method, is usually used to, separate coloured, substances from, each other?
(a) Simple distillation
(b) Chromatography
(c) Evaporation
(d) Crystallization
42. The particles, left behind, on the filter paper, in the filtration, process are called: ______________?
(a) Filtrate
(b) Residue
(c) Distillate
(d) None of theses
43. What atoms, are found, methane (CH4)?
(a) Carbon and 4 hydrogen
(b) I carbon & 1 hydrogen
(c)1 carbon & 4 hydrogen
(d) 4 carbon & 1 hydrogen
44. The correct, order is, _______________________?
(a)Dissolving- filtration-evaporation
(b) Evaporation -filtration -evaporation
(c) dissolve- evaporation-filtration
(d) none of theses
45. Which of these, gasses are present, in maximum amount, of air?
(a)Oxygen
(b) nitrogen
(c) chlorine
(d) hydrogen
46. Oxygen, is not, necessary, for: ________________________-?
(a)Rutting
(b)Combustion
(c) Photosynthesis
(d) respiration
47. Carbon, deride is, used for: _______________________-?
(a) Soft drinks
(b) Photosynthesis
(c) Fire extinguish
(d) all of those
48. Which, is true for, nitrogen?
(a)Used as dry ice
(b) used in respiration
(c) used as coolant
(d) used in combustion
49. What is the, volume of oxygen, & carbon, dioxide?
(a) 21% carbon dioxide & 0.03% oxygen
(b) 0.03% carbon dioxide & 78 % oxygen
(c) 0.03% oxygen & 78% carbon dioxide
(d) none of these
50. “Insert gases” are not, uses in?
(a)Electric bulbs
(b) Photosynthesis
(c) Sign boards
(d) Weather balloons
