Chemistry
Chemistry GK – Questions & Answer
Chemistry is the science that studies matter, elements, compounds, and chemical reactions. These basic Chemistry GK questions help improve scientific knowledge and are useful for students, quizzes, and competitive exams.
Practice questions 1-25
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Chemistry GK – Questions & Answers
Questions 1–25
1. Who is known as the Father of Modern Chemistry? – Antoine Lavoisier
2. What is the lightest element in the periodic table? – Hydrogen
3. What is the chemical symbol of gold? – Au
4. Which gas is essential for respiration? – Oxygen
5. The atomic number of carbon is? – 6
6. Which acid is found in lemon? – Citric Acid
7. What is the common name of sodium chloride? – Common Salt
8. What is the pH value of pure water? – 7 (Neutral)
9. Which gas is known as laughing gas? – Nitrous Oxide (N₂O)
10. What is the chemical symbol of iron? – Fe
11. Which metal is liquid at room temperature? – Mercury
12. Which element is necessary for the formation of hemoglobin? – Iron
13. What is the hardest natural substance on Earth? – Diamond
14. Which gas is used in fire extinguishers? – Carbon Dioxide (CO₂)
15. What is the chemical symbol for lead? – Pb
16. Who proposed the atomic theory? – John Dalton
17. Which element has the highest electronegativity? – Fluorine
18. What is the chemical name of washing soda? – Sodium Carbonate (Na₂CO₃)
19. What is the atomic number of oxygen? – 8
20. Which element is used in pencils? – Carbon (Graphite)
21. Which element is used in making thermometers? – Mercury
22. The noble gases are found in which group of the periodic table? – Group 18
23. Which gas turns limewater milky? – Carbon Dioxide
24. Which is the most abundant element in Earth's crust? – Oxygen
25. What is the main component of natural gas? – Methane (CH₄)
Questions 26–45
26. Which gas is used in balloons? – Helium
27. What is the chemical symbol of silver? – Ag
28. Which acid is present in vinegar? – Acetic Acid
29. What is the chemical formula of ozone? – O₃
30. Which gas is produced during photosynthesis? – Oxygen
31. Which metal is the best conductor of electricity? – Silver
32. Which chemical is called quicklime? – Calcium Oxide (CaO)
33. What is the chemical symbol of potassium? – K
34. Which gas is known as marsh gas? – Methane (CH₄)
35. Which inert gas is used to fill fluorescent lamps (along with mercury vapor)? – Argon
36. Which acid is used in car batteries? – Sulfuric Acid
37. What is the chemical symbol of sodium? – Na
38. Which gas makes up about 78% of Earth's atmosphere? – Nitrogen
39. What is the chemical symbol of copper? – Cu
40. Which metal is used for making aircraft bodies? – Aluminium
41. Which is the heaviest naturally occurring element? – Uranium
42. Which element has the chemical symbol Zn? – Zinc
43. Which element is used in nuclear reactors as fuel? – Uranium
44. Which acid is called the "King of Chemicals"? – Sulfuric Acid
45. Which element is used in making semiconductor devices? – Silicon
Questions 46–65
46. What is the chemical symbol of calcium? – Ca
47. Which element is called the "building block of life"? – Carbon
48. Which gas is commonly known as "dry ice" in its solid form? – Carbon Dioxide
49. What is the atomic number of hydrogen? – 1
50. Which gas mixture is known as "water gas"? – Carbon monoxide + Hydrogen
51. What is the atomic number of helium? – 2
52. What is the chemical formula of ammonia? – NH₃
53. Which gas is used for welding? – Acetylene
54. Which element has the symbol Sn? – Tin
55. What is the molecular formula of glucose? – C₆H₁₂O₆
56. Which gas is used to preserve food items? – Nitrogen
57. Which metal is sometimes called the "metal of the future" for its strength and low weight? – Titanium
58. Which element is liquid at room temperature, other than mercury? – Bromine
59. What is the chemical formula of sulfuric acid? – H₂SO₄
60. Which gas gives soda water its fizz? – Carbon Dioxide
61. Which element has the chemical symbol Mg? – Magnesium
62. Which element has the atomic number 79? – Gold
63. What is the chemical formula of table sugar (sucrose)? – C₁₂H₂₂O₁₁
64. Which gas mixture is known as "coal gas"? – Methane, Hydrogen, and Carbon Monoxide
65. Which is the lightest metal? – Lithium
Questions 66–85
66. Which element has the atomic number 26? – Iron (Fe)
67. What is the chemical formula of baking soda? – NaHCO₃
68. Which element is called quicksilver? – Mercury
69. What is the chemical symbol of phosphorus? – P
70. Which gas is used in the manufacture of fertilizers? – Ammonia
71. What is the atomic number of neon? – 10
72. Which metal is used for galvanization? – Zinc
73. Which gas is used in soda water? – Carbon Dioxide
74. Which element has the atomic number 17? – Chlorine
75. Which gas is used for ripening of fruits? – Ethylene
76. Which gases combine in the Haber process to produce ammonia? – Nitrogen and Hydrogen
77. Which gas from incomplete combustion is highly poisonous? – Carbon Monoxide (CO)
78. Which gas is used in fuel cells as a clean energy source? – Hydrogen
79. Which is the most abundant gas in the Sun? – Hydrogen
80. Which chemical is commonly used as a tear gas? – Chloropicrin
81. What is the chemical symbol of uranium? – U
82. Which is the lightest noble gas? – Helium
83. Which alloy is used in making railway tracks? – Steel (Iron + Carbon)
84. Which element has the atomic number 92? – Uranium
85. Which element has the atomic number 82? – Lead
Questions 86–105
86. Which element is sometimes called the "king of metals"? – Gold
87. Which element is used in the vulcanization of rubber? – Sulphur
88. Which metal is the most malleable (can be beaten into the thinnest sheets)? – Gold
89. What is the atomic number of nitrogen? – 7
90. Which acid is found in tamarind? – Tartaric Acid
91. Which form of carbon is a good conductor of electricity? – Graphite
92. What is the chemical symbol of tungsten? – W
93. Which gas is released when zinc reacts with hydrochloric acid? – Hydrogen
94. Which element is widely used in making LEDs and semiconductors? – Gallium
95. Which gas is responsible for acid rain? – Sulfur Dioxide (SO₂)
96. Which mineral compound is known as "fool's gold"? – Iron Pyrite
97. Which acid is present in curd/yogurt? – Lactic Acid
98. Which metals are added to iron to make stainless steel? – Chromium and Nickel
99. Which element currently has the highest atomic number in the periodic table (as of 2025)? – Oganesson (Og, 118)
100. Which chemical is commonly used to purify drinking water? – Chlorine
101. Which metal is theoretically the most reactive, though too unstable/rare to be tested directly? – Francium (Cesium is often used as the practical "most reactive" answer in exams)
102. Which is the most reactive non-metal? – Fluorine
103. Which element is essential for the formation of bones and teeth? – Calcium
104. Which metal is widely used in electrical wiring due to its high conductivity? – Copper
105. Which element is used as fuel in nuclear power plants? – Uranium
