Metals and Non-metals — Class 10 Science

What CBSE examines here (2026-27). This chapter is unchanged by rationalisation — physical/chemical properties, the reactivity series, ionic bonding, metallurgy and corrosion are all still here, across five in-text question sets (15 questions) and one end-of-chapter Exercise (16 questions). The full reactivity series (K, Na, Ca, Mg, Al, Zn, Fe, Pb, [H], Cu, Hg, Ag, Au) genuinely belongs to this chapter — it's the one referenced (but not spelled out) back in Chapter 1.

"Iron built civilisations. Silicon powers smartphones. Carbon underlies all life. Elements shape destinies."

1. About the Chapter

This chapter explores:

• Physical & chemical properties of metals and non-metals
• Reactivity series of metals
• Ionic compounds formation
• Extraction of metals from ores (metallurgy)
• Corrosion and prevention

Why Important

• Indian metallurgy (steel, aluminium, gold) is major industry
• Foundation for chemistry, materials science
• Critical for engineering

2. Physical Properties

Metals

• Lustrous (shiny) when polished
• Malleable (can be hammered into sheets)
• Ductile (can be drawn into wires)
• Hard (most are; exceptions: Na, K)
• Good conductors of heat and electricity
• High density
• High melting/boiling points (mostly)
• Sonorous (ring when struck)
• Solid at room temperature (except mercury — liquid)

Non-metals

• Dull (not shiny; exception: iodine)
• Brittle (break, don't bend)
• Poor conductors (exception: graphite — carbon)
• Low density
• Low melting/boiling points (mostly)
• Not sonorous
• Solid, liquid, or gas at room temp

Exceptions to Remember

• Mercury (Hg) — only metal LIQUID at room temp
• Bromine (Br) — only non-metal LIQUID at room temp
• Gallium and Caesium — metals with very low melting points (~30°C)
• Carbon (graphite) — non-metal that conducts electricity
• Diamond — hardest natural substance, made of carbon (non-metal)

3. Chemical Properties

Metals — Chemical Reactions

1. With Oxygen → Metal Oxide (BASIC)

• 2Mg + O₂ → 2MgO
• 4Al + 3O₂ → 2Al₂O₃

Metal oxides are BASIC (turn red litmus blue when dissolved in water).

2. With Water → Metal Hydroxide + H₂

• 2Na + 2H₂O → 2NaOH + H₂↑ (violent reaction!)
• Mg + 2H₂O → Mg(OH)₂ + H₂ (slow)
• Some metals (Au, Ag, Pt) DON'T react with water

3. With Acids → Salt + H₂

• Mg + 2HCl → MgCl₂ + H₂↑
• Au, Ag don't react with acids

4. With Other Metal Salts → Displacement

• Zn + CuSO₄ → ZnSO₄ + Cu (Zn more reactive than Cu)

Non-metals — Chemical Reactions

1. With Oxygen → Non-metal Oxide (ACIDIC)

• C + O₂ → CO₂ (acidic when dissolved)
• S + O₂ → SO₂

Non-metal oxides are ACIDIC.

2. With Hydrogen → Hydride

• 2H₂ + O₂ → 2H₂O (water = hydride of oxygen)
• N₂ + 3H₂ → 2NH₃

4. Reactivity Series

What is it?

A list of metals arranged in DECREASING order of reactivity.

Series (most → least reactive)

K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au

(Mnemonic: 'Please Stop Calling My Aunt Zelda In Public Hating Copper Mercury Silver Gold' — many versions exist.)

Importance

• A metal HIGHER in series DISPLACES a metal LOWER from its salt
• Example: Zn + CuSO₄ → ZnSO₄ + Cu (Zn > Cu in series)
• Reverse doesn't happen: Cu + ZnSO₄ → NO REACTION

Position of Hydrogen

Hydrogen is in the middle. Metals ABOVE H displace H from acids (give H₂). Metals BELOW H don't.

5. Ionic Compounds

Formation

• Metal loses electron(s) → forms positive ion (cation)
• Non-metal gains electron(s) → forms negative ion (anion)
• Cation and anion attract → IONIC BOND

Example: NaCl

• Na → Na⁺ + e⁻ (loses 1 electron)
• Cl + e⁻ → Cl⁻ (gains 1 electron)
• Na⁺ and Cl⁻ attract: NaCl

Properties of Ionic Compounds

• Crystalline solids
• High melting/boiling points
• Soluble in water (mostly)
• Conduct electricity when MOLTEN or DISSOLVED (not in solid state)
• Brittle — break along crystal planes

6. Extraction of Metals (Metallurgy)

Steps in Metallurgy

1. Mining — get ore from earth
2. Concentration — separate useful mineral
3. Reduction — extract metal from ore
4. Refining — purify the metal

Reduction Methods Depend on Reactivity

Most Reactive (K, Na, Ca, Mg, Al):

• Use ELECTROLYSIS (electric current)
• E.g., aluminium from bauxite: 2Al₂O₃ → 4Al + 3O₂

Moderately Reactive (Zn, Fe, Pb, Cu):

• Roast or calcine ore to oxide
• Then REDUCE with carbon: 2ZnO + C → 2Zn + CO₂

Least Reactive (Hg, Ag, Au):

• Often found in NATIVE form (pure)
• Heating alone may suffice: 2HgS + 3O₂ → 2HgO + 2SO₂; 2HgO → 2Hg + O₂

Indian Metallurgy

• India was first to extract zinc (Zawar, Rajasthan, ~1200 BCE)
• Famous for iron pillar at Mehrauli, Delhi (1600 years old, no rust!)
• Damascus steel — Indian origin
• Modern: Tata Steel, JSW, SAIL — world-leading

7. Common Ores

8. Corrosion (Detailed)

What is Corrosion?

Slow eating away of metals due to action of air, moisture, chemicals.

Examples

• Rusting of iron (Fe₂O₃·xH₂O — reddish-brown)
• Tarnishing of silver (Ag₂S — black, by sulphur in air)
• Greening of copper (CuCO₃·Cu(OH)₂ — basic copper carbonate)

Prevention

• Painting
• Greasing/oiling
• Galvanisation (zinc coating — protects iron)
• Electroplating (silver/chromium plating)
• Alloying (mixing metals — stainless steel = Fe + Cr + Ni)
• Sacrificial protection (magnesium block on iron)

9. Worked Examples

Example 1: Reactivity

Can Cu displace Zn from ZnSO₄?

• NO. In activity series, Zn > Cu.
• Only Zn can displace Cu (from CuSO₄), not vice versa.

Example 2: Identification

A non-metal liquid at room temperature.

• BROMINE (Br₂). Only non-metal liquid at room temp.

Example 3: Property

Why are wires made of copper?

• Cu is excellent CONDUCTOR of electricity. Also DUCTILE (can be drawn into thin wires).

Example 4: Ionic Formation

How does magnesium chloride form?

• Mg loses 2 e⁻ → Mg²⁺
• Each Cl gains 1 e⁻ → Cl⁻
• Need 2 Cl⁻ per Mg²⁺ → MgCl₂

Example 5: Reduction Method

Why is aluminium extracted by electrolysis, not by reduction with carbon?

• Al is HIGH in reactivity series. C cannot reduce it.
• Electrolysis is needed for highly reactive metals.

10. Common Mistakes

1. All metals are solids

   • Mercury (Hg) is LIQUID at room temperature.

2. Non-metals don't conduct

   • GRAPHITE (form of carbon) conducts electricity.

3. Activity series memorisation

   • K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au

4. Wrong oxide nature

   • METAL OXIDES are BASIC. NON-METAL OXIDES are ACIDIC.

5. Ionic compounds conduct in solid state

   • NO. They conduct only when MOLTEN or DISSOLVED.

11. Indian Heritage

Ancient Metallurgy

• Iron Pillar at Mehrauli (Delhi, ~4th century CE) — pure iron, no rust in 1600 years!
• Damascus steel (wootz steel from South India) — legendary for sharp blades
• Brass and bronze widely used in temple bells, coins
• Zinc smelting in Zawar (Rajasthan) ~1200 BCE — earliest in world

Modern

• India is #2 steel producer (2024)
• Major iron ore exports (Odisha, Karnataka)
• Hindalco (aluminium), Vedanta major companies

12. Conclusion

Metals and Non-metals are FUNDAMENTAL CHEMISTRY:

• Properties differ (lustrous vs dull, conducting vs not)
• Reactions with O₂, H₂O, acids
• Reactivity Series predicts behaviour
• Metallurgy turns ores into useful metals
• Indian heritage in metallurgy is rich

Master:

• Properties (physical and chemical)
• Activity series
• Common reactions
• Extraction methods
• Common ores

This is HIGH-MARK chapter. Practice 15+ problems.

Metals built our civilisation. Understanding them is understanding modern life.