Materials: Metals and Non-Metals – MCQs with Answers and Explanations
Class 8 • Science
Chapter 4 — Materials: Metals and Non-Metals
50 Topic-wise MCQs (NCERT aligned) — with answers and clear explanations for CBSE Class 8
CBSE Board Examinations — Systematic overview
Paper Type
Objective & Subjective (MCQs appear in periodic tests and sample papers)
Chapter Weight
Short answer & MCQs from this chapter typically: 6–8 marks in unit tests / term exams
Skills Tested
Conceptual understanding — physical & chemical properties, reactivity, corrosion, uses
Tips
Memorize reactivity series, typical reactions (with O2, H2O, acids) and real-life examples (rusting, alloys)
Topic 1 — Physical Properties of Metals (10 MCQs)
-
1. Which of the following is NOT a typical physical property of most metals?Answer: CMetals are generally good conductors of heat; being a poor conductor is not a typical property of metals. They are malleable, sonorous and lustrous.
-
2. Which property allows a metal to be drawn into wires?Answer: BDuctility is the property that allows metals to be drawn into thin wires. Malleability is for making sheets.
-
3. Which of these metals is known for being non-magnetic?Answer: CCopper is not magnetic. Iron, nickel and cobalt are magnetic metals.
-
4. The shining appearance of metals is called:Answer: CLuster is the term used for the shiny appearance of metals when polished.
-
5. Which physical property explains why metals can be hammered into thin sheets?Answer: BMalleability is the ability of metals to be beaten into sheets without breaking.
-
6. Metals are generally good conductors of electricity because they have:Answer: AFree (delocalized) electrons in the metallic bond allow easy flow of electric current.
-
7. Which metal is soft enough to be cut with a knife at room temperature?Answer: ASodium is a very soft metal (alkali metal) and can be cut with a knife. Gold is soft too but sodium is the classic example in NCERT experiments.
-
8. The property of metals to produce a ringing sound when struck is called:Answer: BSonority is the property of metals by which they produce a ringing sound on being struck.
-
9. Which of the following metals has the highest electrical conductivity?Answer: BCopper is widely used for electrical wiring because it has very high electrical conductivity.
-
10. Which statement is true about metals?Answer: BMetals generally have luster and are malleable; other options are incorrect generalizations.
Topic 2 — Physical Properties of Non-metals (8 MCQs)
-
11. Which of the following is a typical property of non-metals?Answer: CMost non-metals are poor conductors of heat and electricity and are neither malleable nor sonorous.
-
12. Which non-metal is a good conductor of electricity?Answer: CGraphite, an allotrope of carbon, conducts electricity due to delocalised electrons in its layers.
-
13. Which of the following non-metals exists as a gas at room temperature?Answer: CChlorine is a greenish-yellow gas at room temperature. Iodine is a solid that sublimes; carbon and sulfur are solids.
-
14. Non-metals are generally:Answer: BNon-metals are often dull and brittle (if solid) and poor conductors, unlike metals.
-
15. Which non-metal is used in antiseptic solutions and as a disinfectant in schools and homes?Answer: BChlorine is widely used as a disinfectant (in diluted form) and in bleaching; it's a reactive non-metal gas.
-
16. Which of these non-metals is a good conductor of heat?Answer: BDiamond (an allotrope of carbon) is an excellent conductor of heat (thermal conductor) though it is an electrical insulator.
-
17. Which non-metal is essential for respiration of animals?Answer: BOxygen is necessary for respiration. Nitrogen is inert in breathing mixtures and not used metabolically in its gaseous form.
-
18. Which of these non-metals is used to make pencils?Answer: AGraphite is a form of carbon used as the "lead" in pencils because its layers slide off onto paper.
Topic 3 — Chemical Properties: Reaction with Oxygen (6 MCQs)
-
19. Which product is formed when magnesium reacts with oxygen?Answer: AMagnesium reacts with oxygen to form magnesium oxide (Mg + O2 → MgO).
-
20. Which non-metal reacts vigorously with oxygen to give oxide used in burning and respiration?Answer: CCarbon reacts with oxygen to form carbon dioxide (complete combustion) or carbon monoxide (incomplete). Carbon dioxide is involved in respiration cycles.
-
21. Rusting is an example of:Answer: BRusting involves iron reacting with oxygen (and water) to form iron oxides — primarily a reaction with oxygen.
-
22. Which of these metals burns with a bright white flame and produces white ash (oxide)?Answer: BMagnesium burns with a bright white flame forming magnesium oxide (white ash).
-
23. Which oxide is formed when sulphur burns in oxygen?Answer: ASulphur burns to form sulphur dioxide (SO2). Under further oxidation it can form SO3, but primary product is SO2.
-
24. Which of the following is a correct general observation for metals when heated in oxygen?Answer: BOn heating in presence of oxygen many metals react to form their metal oxides.
Topic 4 — Chemical Properties: Reaction with Water (5 MCQs)
-
25. Which metal reacts vigorously with cold water to produce hydrogen gas?Answer: BSodium (an alkali metal) reacts vigorously with cold water to produce sodium hydroxide and hydrogen gas.
-
26. Which metal does NOT react with water at room temperature?Answer: BIron does not react readily with cold water (it reacts slowly with steam or hot water). Alkali metals like potassium and sodium react vigorously; calcium reacts with water moderately.
-
27. When zinc reacts with steam, which product is formed along with hydrogen?Answer: AZinc reacts with steam to form zinc oxide (ZnO) and hydrogen gas.
-
28. Which group of elements reacts with water to give alkaline solutions and hydrogen gas?Answer: BAlkali metals (Group 1) react with water to produce metal hydroxides (alkaline solutions) and hydrogen gas.
-
29. Which of the following is the correct reaction when sodium reacts with water?Answer: ASodium reacts with water to form sodium hydroxide (NaOH) and hydrogen gas (H2).
Topic 5 — Chemical Properties: Reaction with Acids (5 MCQs)
-
30. Which gas is liberated when a metal reacts with dilute hydrochloric acid?Answer: CMetals above hydrogen in the activity series react with dilute acids to produce hydrogen gas.
-
31. Which metal does not react with dilute HCl to produce hydrogen?Answer: BCopper is less reactive than hydrogen and does not displace hydrogen from dilute acids; therefore it does not produce H2.
-
32. Which of the following metals will react with dilute sulphuric acid to give hydrogen?Answer: CZinc is more reactive than hydrogen and reacts with dilute sulphuric acid to produce hydrogen gas and zinc sulphate.
-
33. Which of the following is a correct observation when iron reacts with dilute acid?Answer: BIron reacts with dilute acids to give iron salts and hydrogen gas is evolved.
-
34. Which of the following does NOT react with dilute acids to produce hydrogen?Answer: BCopper being below hydrogen in activity series does not react with dilute acids to produce hydrogen gas.
Topic 6 — Chemical Properties: Reaction with Salt Solutions & Displacement Reactions (6 MCQs)
-
35. When a metal A is placed in a solution of metal B salt and A displaces B, what does it mean about A?Answer: BIf A displaces B from its salt solution, A is more reactive than B (activity series concept).
-
36. Zinc will displace which metal from its salt solution?Answer: BZinc is more reactive than copper and thus displaces copper from its salt solution (Zn + CuSO4 → ZnSO4 + Cu).
-
37. Which metal will NOT be displaced by iron from its salt solution?Answer: CZinc is more reactive than iron, so iron cannot displace zinc from its solutions; iron can displace copper and silver which are less reactive.
-
38. Which of these equations shows a displacement reaction?Answer: ACopper displacing silver from silver nitrate solution is a displacement reaction (Cu + 2AgNO3 → Cu(NO3)2 + 2Ag).
-
39. Which metal will displace hydrogen from dilute acids?Answer: CZinc is more reactive than hydrogen and thus reacts with dilute acids to produce hydrogen gas (displaces hydrogen).
-
40. A metal placed in copper sulphate solution results in a grey coating of copper on the metal. Which metal could it be?Answer: BZinc will displace copper from copper sulphate solution and copper metal deposits as a grey coating on zinc.
Topic 7 — Corrosion and Prevention (5 MCQs)
-
41. Rusting of iron requires which of the following?Answer: CRusting requires both oxygen and water; in the absence of either one rusting is greatly reduced.
-
42. Which method is NOT used to prevent rusting?Answer: DLeaving iron in water will encourage rusting; the other methods prevent rusting by excluding oxygen/water or providing sacrificial protection.
-
43. Galvanization protects iron from rusting because zinc:Answer: BZinc is more reactive and acts as a sacrificial metal; it corrodes instead of iron, protecting it.
-
44. Which of the following is formed when iron rusts?Answer: BRust is mainly hydrated iron(III) oxide — generally referred to as iron oxide compounds.
-
45. Which of the following best prevents rusting of iron gates in coastal areas?Answer: CCoastal areas have salty, moist air; painting, galvanizing and maintenance are combined measures to effectively prevent rust.
Topic 8 — Alloys and Uses of Metals (5 MCQs)
-
46. Bronze is an alloy of:Answer: BBronze is primarily an alloy of copper and tin and is harder than pure copper.
-
47. Brass (used in musical instruments) is an alloy of:Answer: BBrass is an alloy of copper and zinc, known for its bright gold-like appearance and good acoustic properties.
-
48. Stainless steel is an alloy mainly of iron, carbon and which other element to prevent rusting?Answer: BChromium is added to steel to form a protective oxide layer that prevents rusting; stainless steel often contains nickel as well but chromium is the key anti-rusting component.
-
49. Which alloy would be best for making cutting edge tools (e.g., knives)?Answer: CHigh carbon steel is hard and can hold a sharp cutting edge, making it suitable for cutting tools.
-
50. Which of the following explains why alloys are often preferred over pure metals?Answer: BAlloys are engineered to have desirable combinations of properties (e.g., increased strength, corrosion resistance) compared to pure metals.