1. Which element has the lowest melting point?
a) Iron
b) Nitrogen
c) Iodine
d) Lead
Answer: b
2. The filament of an electric bulb is made of:
a) Magnesium
b) Lead
c) Tin
d) Tungsten
Answer: d
3. Which element among the following has the lowest melting point?
a) Oxygen
b) Platinum
c) Sodium
d) Tin
Answer: a
4. Which of the following has the lowest melting point?
a) Chromium
b) Hydrogen
c) Zinc
d) Silver
Answer: b
5. Fullerene is a crystalline allotrope of carbon containing:
a) 100 carbon atoms
b) 80 carbon atoms
c) 60 carbon atoms
d) 40 carbon atoms
Answer: c
6. The chemical formula of ammonium nitrate is:
a) (NH₃)₂NO₃
b) NH₄NO₃
c) NH₄(NOC)
d) NH₂NO₃
Answer: b
7. Which property is typically observed in non-metals?
a) Brittleness
b) Conductivity
c) Ductility
d) Malleability
Answer: a
8. Which element has the lowest melting point?
a) Titanium
b) Sulphur
c) Argon
d) Zinc
Answer: c
9. One carat of diamond is equivalent to:
a) 100 mg
b) 150 mg
c) 200 mg
d) 250 mg
Answer: c
10. Chemically, washing soda is:
a) Aluminium bicarbonate
b) Sodium bicarbonate
c) Aluminium sulphate
d) Sodium carbonate
Answer: d
11. Which of the following is used as a lubricant?
a) Germanium
b) Sulphur
c) Graphite
d) Indium
Answer: c
12. Which of the following statements is incorrect?
a) Hydrogen has about 1/3 the mass of tritium
b) Deuterium is known as heavy hydrogen
c) Deuterium has one neutron
d) Protium is the rarest isotope of hydrogen
Answer: d
13. The material used in pencils is:
a) Charcoal
b) Graphite
c) Sulphur
d) Phosphorus
Answer: b
14. Zeolite is chemically:
a) Hydrated ferric oxide
b) Hydrated sodium aluminium silicate
c) Sodium hexametaphosphate
d) Sodium tetraborate
Answer: b
15. The essential element in chlorophyll is:
a) Sodium
b) Potassium
c) Manganese
d) Magnesium
Answer: d
16. Which metal can be used as an electromagnet?
a) Iron
b) Copper
c) Nickel
d) Cobalt
Answer: a
17. The purest form of carbon is:
a) Anthracite
b) Lampblack
c) Graphite
d) Wood charcoal
Answer: a
18. Which two metals have natural colors other than silver?
a) Nickel and Zinc
b) Copper and Gold
c) Palladium and Platinum
d) Sodium and Magnesium
Answer: b
19. Silica gel is a:
a) Moisturizer
b) Flavouring agent
c) Drying agent
d) Food preservative
Answer: c
20. To achieve noble gas configuration, barium loses:
a) 1 electron
b) 2 electrons
c) 3 electrons
d) 4 electrons
Answer: b
21. Which gas is used as an anaesthetic?
a) Methane
b) Carbon dioxide
c) Nitrous oxide
d) Nitrogen
Answer: c
22. Which of the following is a poor conductor of electricity?
a) Iron
b) Lead
c) Silver
d) Gold
Answer: b
23. The most reactive allotrope of phosphorus is:
a) Black phosphorus
b) White phosphorus
c) Violet phosphorus
d) Red phosphorus
Answer: b
24. Metal luster is primarily due to:
a) High atomic packing density
b) Polished surfaces
c) Reflection of light by free electrons
d) Absorption of light by metal sockets
Answer: c
25. Which gas is used in the manufacture of bleaching powder?
a) Oxygen
b) Hydrogen
c) Nitrogen
d) Chlorine
Answer: d
26. Which element behaves as both a metal and a non-metal?
a) Argon
b) Carbon
c) Xenon
d) Boron
Answer: d
27. Why is argon used in arc welding?
a) It is inert and prevents metal oxidation
b) It lowers the melting point of metals
c) It has high flammability
d) It has high calorific value
Answer: a
28. Brown coal is commonly known as:
a) Anthracite
b) Bituminous
c) Coke
d) Lignite
Answer: d
29. Which fuel causes the least environmental pollution?
a) Diesel
b) Kerosene
c) Hydrogen
d) Coal
Answer: c
30. The “king of metals” is:
a) Gold
b) Silver
c) Iron
d) Aluminium
Answer: a
31. The purest form of natural water is:
a) Rainwater
b) Lake water
c) River water
d) Sea water
Answer: a
32. Pure gold content in 18-carat gold is:
a) 100%
b) 80%
c) 75%
d) 60%
Answer: c
33. The best conductor among the following is:
a) Graphite
b) Diamond
c) Peat
d) Charcoal
Answer: a
34. The only metal that is liquid at room temperature is:
a) Mercury
b) Platinum
c) Lead
d) Zinc
Answer: a
35. Which metal has the lowest melting point among the following?
a) Gold
b) Silver
c) Mercury
d) Copper
Answer: c
36. The second most abundant element in the sun, after hydrogen, is:
a) Helium
b) Neon
c) Argon
d) Oxygen
Answer: a
37. The highest grade of hard coal is:
a) Anthracite
b) Bituminous
c) Lignite
d) Peat
Answer: a
38. The noble gas used in cancer treatment is:
a) Helium
b) Argon
c) Krypton
d) Radon
Answer: d