5. The luster of a metal is due to

7. The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is

8. The following are the half lives of four active isotopes. Which one of the following is the most dangerous to handle?

9. Diamond is harder than graphite because of :

10. The hardest form of carbon is

11. Carbon dioxide is

13. The main source of Naphthalene is

15. The most malleable metal is

16. The ionic radii of N^3-, O^2-, F^– and Na⁺ follows the order

21. The most important ore of aluminium is

23. The method that cannot be used for removing permanent hardness of water is

24. The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2^nd orbit to 3^rd orbit is

26. The maximum number of covalent formed by nitrogen is

29. The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is

30. The maximum number of isomers for an alkene with molecular formula C₄H₈ is

31. The main buffer system of the human blood is

32. For extinguishing fire, we use

35. The heat energy produced when the human body metabolises 1 gram of fat is

36. Air is said to be saturated when :

37. The heat required to raise the temperature of body by 1 K is called

38. The major constituent of air is

41. The major constituent of air is

43. The nucleus of an atom consists of

45. The law which states that the amount of gas dissolved in a liquid is proportional to its partial pressure is

49. The most commonly used bleaching agent is

50. The number of moles of solute present in 1 kg of a solvent is called its

53. The most electropositive elements among the following is

55. The molecules of which gas have highest speed?

56. The number of d-electrons in Fe²⁺ (Z = 26) is not equal to that of

57. The gas used to extinguish fire is

58. The number of waves in n x 10^th Bohr’s orbit are

60. The iron ore magnetite consists of

61. Which is the highest quality of hard coal?

63. The hottest part of the gas flame is known as

64. One carat of diamond is equal to

65. Which among the following coal contains 90 per cent of carbon?

66. The mineral containing both magnesium and calcium is

67. Which of the following phenomenon is considered responsible for Global Warming?

69. The main active constituent of tea and coffee is

71. The organic reaction represented by equation CH₃ – CH = O + H₂NOH gives CH₃ – CH – NH + H₂O is an example of

72. The monomer of polythene is

73. The percentage of Nitrogen in Air is

74. The metal that is used as a catalyst in the hydrogenation of oils is

75. The inherited traits of an organism are controlled by

77. Dry ice is

78. The gas used in the manufacture of vanaspati from vegetable oil is

79. The mass of P₄O₁₀ that will be obtained from the reaction of 1.33 gram of P₄ and 5.07 of oxygen is

83. The hydronium ion is

84. The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in

85. The material which can be deformed permanently by heat and pressure is called a

86. Dry powder fire extinguishers contain

87. Diamonds are glittering and attractive because light incident on them undergoes

88. The mass of one Avogadro number of helium atom is

90. The National Chemical Laboratory is situated in

91. The oldest rocks in the earth’s crust were once molten, and came from deep inside the earth. The molten rock, called magma, spewed out in volcanic eruptions during the earth’s early life and solidified into hard rock’s called

93. Dry ice is the solid form of :

94. The octane number of zero is assigned to

95. The nucleus of a hydrogen atom consists of

96. The most abundant constituent of atmospheric air is :

98. The inert gases are ____ in water.

99. The number of g-molecule of oxygen in 6.02 x 10²⁴ CO molecules is