🔩 Metals and Non-Metals – Class 10 Science MCQs

Part 3: Corrosion, Alloys, Properties of Non-Metals & Uses (Q51–Q75)

Q51. The reddish-brown coating on iron objects is called:

A. Tarnish
B. Patina
C. Rust
D. Scale

✅ Correct Answer: C. Rust

Explanation: Rust is hydrated ferric oxide Fe₂O₃·xH₂O formed due to oxidation in the presence of air and moisture.

Q52. The black coating formed on silver ornaments is due to:

A. Ag₂O
B. Ag₂S
C. AgCl
D. AgNO₃

✅ Correct Answer: B. Ag₂S

Explanation: Silver reacts with hydrogen sulphide gas in air → forms silver sulphide (black).

Q53. The green layer formed on copper vessels is:

A. CuCl₂
B. Basic copper carbonate
C. CuO
D. CuSO₄

✅ Correct Answer: B. Basic copper carbonate (CuCO₃·Cu(OH)₂)

Q54. Corrosion of aluminium is less damaging because:

A. Aluminium never corrodes
B. A protective oxide layer is formed
C. Aluminium reacts very slowly
D. Aluminium is soft metal

✅ Correct Answer: B. A protective oxide layer is formed

Q55. Rusting of iron requires:

A. Oxygen only
B. Water only
C. Both oxygen and water
D. Neither oxygen nor water

✅ Correct Answer: C. Both oxygen and water

Q56. Which of the following prevents rusting of iron?

A. Painting
B. Greasing
C. Galvanization
D. All of these

✅ Correct Answer: D. All of these

Q57. Galvanization is the process of coating iron with:

A. Aluminium
B. Copper
C. Zinc
D. Tin

✅ Correct Answer: C. Zinc

Q58. Bronze is an alloy of:

A. Copper and zinc
B. Copper and tin
C. Iron and carbon
D. Iron and chromium

✅ Correct Answer: B. Copper and tin

Q59. Brass is an alloy of:

A. Copper and tin
B. Copper and zinc
C. Iron and carbon
D. Iron and chromium

✅ Correct Answer: B. Copper and zinc

Q60. Stainless steel is an alloy of:

A. Iron, carbon, chromium, nickel
B. Iron and zinc
C. Iron and copper
D. Iron and aluminium

✅ Correct Answer: A. Iron, carbon, chromium, nickel

Q61. Which property of alloys makes them useful?

A. They are pure substances
B. They have improved strength and resistance to corrosion
C. They are always cheaper than metals
D. They are natural

✅ Correct Answer: B. They have improved strength and resistance to corrosion

Q62. Solder is an alloy of:

A. Lead and copper
B. Lead and tin
C. Lead and aluminium
D. Lead and zinc

✅ Correct Answer: B. Lead and tin

Explanation: Solder is used in electrical work due to low melting point.

Q63. Which is NOT a property of non-metals?

A. Brittle
B. Poor conductor of electricity
C. Malleable
D. Non-sonorous

✅ Correct Answer: C. Malleable

Q64. Which non-metal is lustrous?

A. Sulphur
B. Iodine
C. Phosphorus
D. Carbon

✅ Correct Answer: B. Iodine

Explanation: Iodine crystals shine with metallic lustre.

Q65. Which non-metal exists as a liquid at room temperature?

A. Iodine
B. Bromine
C. Sulphur
D. Phosphorus

✅ Correct Answer: B. Bromine

Q66. Which non-metal conducts electricity?

A. Diamond
B. Sulphur
C. Graphite
D. Phosphorus

✅ Correct Answer: C. Graphite

Q67. Which non-metal forms the basis of organic life?

A. Oxygen
B. Nitrogen
C. Carbon
D. Phosphorus

✅ Correct Answer: C. Carbon

Q68. Which non-metal is used for disinfecting water?

A. Sulphur
B. Phosphorus
C. Chlorine
D. Nitrogen

✅ Correct Answer: C. Chlorine

Q69. Which non-metal is used in the vulcanization of rubber?

A. Sulphur
B. Phosphorus
C. Carbon
D. Chlorine

✅ Correct Answer: A. Sulphur

Q70. Which non-metal is stored under water because it catches fire in air?

A. Sulphur
B. Phosphorus
C. Bromine
D. Carbon

✅ Correct Answer: B. Phosphorus (white phosphorus)

Q71. Diamond is:

A. Hard and conducts electricity
B. Soft and non-conductor
C. Hard and non-conductor
D. Soft and conductor

✅ Correct Answer: C. Hard and non-conductor

Q72. Graphite is used as a lubricant because:

A. It is soft and slippery
B. It is brittle
C. It is a conductor
D. It is shiny

✅ Correct Answer: A. It is soft and slippery

Q73. Which non-metal is used in the manufacture of fertilizers?

A. Nitrogen
B. Phosphorus
C. Potassium
D. Both A and B

✅ Correct Answer: D. Both A and B

Q74. Which non-metal is used in matchbox heads?

A. Carbon
B. Sulphur
C. Phosphorus
D. Iodine

✅ Correct Answer: C. Phosphorus (red phosphorus)

Q75. Which non-metal is essential for respiration?

A. Nitrogen
B. Oxygen
C. Carbon
D. Sulphur

✅ Correct Answer: B. Oxygen

Metals and Non-metals Class 10, CBSE Class 10 Science MCQs, NCERT Class 10 science questions, Class 10 Science exam practice, Online learning Science Class 10, metals and non-metals class 10 mcqs with answers, cbse class 10 science metals and non-metals multiple choice questions, ncert class 10 metals and non-metals quiz online, important mcqs for cbse class 10 science metals and non-metals, metals and non-metals class 10 mcqs for online learning