🧭 Introduction
Metals and Non-Metals play an important role in our lives — from the iron that builds bridges to the gold used in jewellery and the oxygen that supports life.
In this chapter, students learn about their properties, chemical reactions, and differences through easy examples and equations. Understanding these basics helps to connect science with daily-life applications.
Q1. Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl₂ solution and aluminium metal
(c) FeSO₄ solution and silver metal
(d) AgNO₃ solution and copper metal
Answer: ✅ (d) AgNO₃ solution and copper metal.
Copper is more reactive than silver and displaces it from silver nitrate solution.
Reaction: Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
Q2. Which of the following methods is suitable for preventing an iron frying pan from rusting?
(a) Applying grease (b) Applying paint (c) Applying a coating of zinc (d) All of the above
Answer: ✅ (d) All of the above.
All these methods prevent air and moisture from reaching iron, thus preventing rusting.
Q3. An element reacts with oxygen to give a compound with a high melting point. The compound is also soluble in water. The element is likely to be —
Answer: ✅ (a) Calcium.
Calcium reacts with oxygen to form calcium oxide (CaO), which has a high melting point and is soluble in water forming calcium hydroxide.
Q4. Food cans are coated with tin and not with zinc because —
Answer: ✅ (c) Zinc is more reactive than tin.
Zinc reacts with acids present in food, spoiling it. Tin is less reactive and hence preferred.
Q5. You are given a hammer, a battery, a bulb, wires, and a switch.
(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Assess the usefulness of these tests.
Answer:
(a) Metals are malleable — they can be hammered into thin sheets, while non-metals break easily.
Also, metals are good conductors of electricity, so the bulb will glow when the metal is connected in a circuit; it will not glow with a non-metal.
(b) These tests help identify conductivity and malleability — key properties that distinguish metals from non-metals.
Q6. What are amphoteric oxides? Give two examples.
Answer: Oxides that react with both acids and bases to form salt and water are called amphoteric oxides.
Examples: Aluminium oxide (Al₂O₃), Zinc oxide (ZnO).
Q7. Name two metals which will displace hydrogen from dilute acids and two metals which will not.
Answer:
Metals that displace hydrogen — Zinc (Zn), Iron (Fe).
Metals that will not — Copper (Cu), Silver (Ag).
Q8. In the electrolytic refining of a metal M, what would you take as the anode, cathode and electrolyte?
Answer:
- Anode: Impure metal M
- Cathode: Pure metal M
- Electrolyte: A solution of a salt of the metal (e.g. CuSO₄ for copper)
During electrolysis, pure metal gets deposited at the cathode.
Q9. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it.
(a) What will be the action of gas on dry and moist litmus paper?
(b) Write a balanced chemical equation for the reaction.
Answer:
(a) The gas formed is sulphur dioxide (SO₂). It has no effect on dry litmus but turns moist blue litmus red — showing acidic nature.
(b) S + O₂ → SO₂
Q10. State two ways to prevent the rusting of iron.
Answer:
1️⃣ Applying paint, oil, or grease.
2️⃣ Galvanisation – coating iron with zinc.
Q11. What type of oxides are formed when non-metals combine with oxygen?
Answer: Acidic or neutral oxides.
Examples: CO₂ (acidic), CO (neutral).
Q12. Give reasons:
(a) Platinum, gold and silver are used for jewellery because they are lustrous, malleable, and resistant to corrosion.
(b) Sodium, potassium and lithium are stored under oil as they react violently with air and moisture.
(c) Aluminium, though reactive, is used for cooking utensils because a protective oxide layer prevents further reaction.
(d) Carbonate and sulphide ores are first converted into oxides since oxides are easier to reduce to metal.
Q13. Why are lemon or tamarind juice used to clean copper vessels?
Answer:
They contain acids which react with the basic copper carbonate layer, dissolving it and making the copper vessel shiny again.
Q14. Differentiate between metal and non-metal on the basis of chemical properties.
| Property | Metals | Non-Metals |
|---|---|---|
| Nature of Oxides | Basic | Acidic |
| Reaction with Acids | Displace Hydrogen | Do not displace Hydrogen |
| Electron Behaviour | Lose electrons (form + ions) | Gain electrons (form – ions) |
Q15. A goldsmith dipped gold ornaments in acid; the weight reduced. Why?
Answer:
The acid (often aqua regia) dissolves a thin metal layer along with dirt, slightly reducing the weight.
Q16. Why is copper used to make hot water tanks and not steel?
Answer:
Copper does not react with water, even at high temperature, while iron rusts easily in the presence of oxygen and moisture. Hence, copper is preferred.
- Chemical Reactions and Equations
- Acids, Bases and Salts
- Metals and Non‑Metals
- Carbon and Its Compounds
- Life Processes
- Control and Coordination
- How Do Organisms Reproduce?
- Heredity and Evolution
- Light – Reflection and Refraction
- The Human Eye and the Colourful World
- Electricity
- Magnetic Effects of Electric Current
- Our Environment
🧩 Conclusion
The chapter “Metals and Non-Metals” helps students understand the basic differences in reactivity, physical and chemical properties of elements.
By learning concepts like corrosion, displacement, and refining, students gain a strong foundation in chemistry and practical applications in daily life.
