Metals and Non-metals Class 10 Notes (2026-27) — CBSE
Class 10 Science Chapter 3 revision notes: properties of metals and non-metals, the reactivity series, ionic bonding, extraction of metals, corrosion and alloys.
Metals and Non-metals — Class 10 Science Notes
Chapter Snapshot
This chapter contrasts metals and non-metals — their physical and chemical properties — then builds the reactivity series and uses it to explain displacement reactions, ionic bonding, and how metals are extracted from their ores (metallurgy). It closes with corrosion and alloys.
Board relevance: dependable source of a reactivity-series/displacement question, a metallurgy (roasting/calcination/reduction) question, and a corrosion or alloy question. Learn the reactivity order and the extraction logic.
Key Concepts & Definitions
Physical properties:
Property Metals Non-metals
Lustre Shiny Dull (except iodine)
State Solid (except mercury) Solid, liquid, or gas
Malleable/ductile Yes (can be beaten into sheets, drawn into wires) No — brittle
Conduction Good conductors of heat & electricity Poor (except graphite)
Sonorous Yes (ring when struck) No
Melting point Generally high (except Na, K — low) Generally low
Exceptions to remember: mercury is a liquid metal; sodium and potassium are so soft they can be cut with a knife; iodine (a non-metal) is lustrous; graphite (a non-metal) conducts electricity; diamond is the hardest natural substance.
Chemical Properties
1. Reaction with oxygen → metal oxides (basic). Amphoteric oxides (Al₂O₃, ZnO) react with both acids and bases.
2Cu + O₂ → 2CuO (black); 4Al + 3O₂ → 2Al₂O₃
Sodium and potassium react so vigorously they are stored in kerosene.
2. Reaction with water → metal hydroxide/oxide + H₂. Reactivity varies: K, Na react violently with cold water; Mg with hot water; Al, Zn, Fe with steam; gold, silver, copper do not react.
2Na + 2H₂O → 2NaOH + H₂ + heat
3. Reaction with acids → salt + hydrogen gas.
Fe + 2HCl → FeCl₂ + H₂↑
(Aqua regia = 3:1 conc. HCl : conc. HNO₃, can even dissolve gold.)
4. Displacement — a more reactive metal displaces a less reactive one from its salt solution.
Fe + CuSO₄ → FeSO₄ + Cu
Reactivity series (decreasing reactivity)
K Na Ca Mg Al Zn Fe Pb (H) Cu Ag Au
Metals above hydrogen displace H₂ from acids; those below (Cu, Ag, Au) do not.
Ionic (Electrovalent) Bonding
Metals lose electrons to form positive ions (cations); non-metals gain electrons to form negative ions (anions). The electrostatic attraction between them is an ionic bond.
Na → Na⁺ + e⁻ ; Cl + e⁻ → Cl⁻ ; then Na⁺ + Cl⁻ → NaCl
Properties of ionic compounds:
- Solids, hard, with high melting/boiling points (strong ionic forces).
- Generally soluble in water, insoluble in kerosene/petrol.
- Conduct electricity when molten or dissolved (ions become free to move), but not in the solid state.
Occurrence and Extraction of Metals
Mineral — a naturally occurring element/compound. Ore — a mineral from which a metal can be profitably extracted. Extraction method depends on the metal's position in the reactivity series.
Reactivity Found as Extraction from oxide
Low (Au, Ag, Pt) Free (native) state Little processing needed
Medium (Fe, Zn, Pb, Cu) Sulphides/carbonates Convert to oxide, then reduce with carbon
High (K, Na, Ca, Mg, Al) Chlorides/oxides Electrolytic reduction (too reactive for carbon)
Steps of metallurgy:
1. Enrichment/concentration of the ore (removing impurities/gangue).
2. Roasting — heat sulphide ore in air → oxide. (2ZnS + 3O₂ → 2ZnO + 2SO₂)
3. Calcination — heat carbonate ore in limited air → oxide. (ZnCO₃ → ZnO + CO₂)
4. Reduction of oxide to metal: carbon for medium-reactivity metals (ZnO + C → Zn + CO); electrolysis for high-reactivity metals.
5. Refining — mostly electrolytic refining (impure metal at anode, pure at cathode).
Thermit reaction (aluminium reduces iron oxide, very exothermic):
Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + heat — used to weld railway tracks.
Corrosion and Alloys
Corrosion — the slow eating away of a metal by air, moisture, or chemicals. Rusting of iron (needs both oxygen and moisture) gives reddish-brown hydrated iron(III) oxide.
Prevention of rusting: painting, oiling/greasing, galvanisation (coating iron with zinc), chrome plating, anodising, and making alloys (like stainless steel).
Alloy — a homogeneous mixture of a metal with another metal or non-metal, made to improve properties (harder, more resistant, better lustre). An amalgam is an alloy containing mercury.
Alloy Composition Note
Steel Iron + carbon Stronger than iron
Stainless steel Iron + chromium + nickel Rust-resistant
Brass Copper + zinc —
Bronze Copper + tin —
Solder Lead + tin Low melting point, used for joining wires
24-carat gold is pure; jewellery uses 22-carat gold (alloyed with copper/silver for hardness). Alloying also changes other properties: pure iron is soft, but adding a small amount of carbon makes hard steel, and adding nickel and chromium makes stainless steel that does not rust. The electrical conductivity and melting point of a metal are generally lower for its alloy than for the pure metal — which is exactly why solder (a lead–tin alloy) melts easily and is useful for joining electrical wires.
Important Question Patterns
1. Reactivity/displacement (2–3 marks): predict whether a reaction occurs (e.g. can copper displace zinc? No); arrange metals by reactivity; explain why metals are stored in kerosene.
2. Metallurgy (3 marks): define roasting vs calcination with equations; extraction method for a given metal from its position in the series; the thermit reaction.
3. Ionic compounds (2–3 marks): electron transfer in NaCl; why ionic compounds have high melting points and conduct only when molten/aqueous.
4. Corrosion (2 marks): conditions for rusting; methods of prevention (galvanisation especially).
5. Alloys (2 marks): composition of brass, bronze, solder, stainless steel; why alloys are made; amalgam.
⚡ Quick Revision
- Metals: lustrous, malleable, ductile, sonorous, conduct heat/electricity. Exceptions: Hg liquid; Na/K soft; graphite conducts; iodine lustrous.
- Reactivity series: K Na Ca Mg Al Zn Fe Pb (H) Cu Ag Au. Above H → displace H₂ from acids.
- Reactions: metal + O₂ → oxide (basic; amphoteric = Al₂O₃, ZnO); metal + acid → salt + H₂↑; displacement by more reactive metal.
- Na/K stored in kerosene (react violently with air/water).
- Ionic compounds: high m.p., soluble in water, conduct when molten/dissolved only.
- Extraction: low reactivity = free; medium = roasting/calcination → carbon reduction; high = electrolysis.
- Roasting (sulphide + air → oxide); calcination (carbonate → oxide). Refining = electrolytic.
- Thermit: Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + heat.
- Galvanisation = zinc coating stops rust. Alloys: brass (Cu+Zn), bronze (Cu+Sn), solder (Pb+Sn), stainless steel (Fe+Cr+Ni); amalgam contains mercury.
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