A fast, one-glance recap of Class 10 Science Chapter 3 (Metals and Non-metals) — for the full worked explanations, see the Solutions.
Revision Notes: Metals and Non-metals
- Physical properties of metals: lustrous, malleable, ductile, good conductors of heat & electricity, sonorous, generally solid (mercury is the exception, liquid at room temperature)
- Physical properties of non-metals: generally dull, brittle, poor conductors (graphite is the exception — conducts electricity); may be solid, liquid (bromine) or gas
- Metal + O₂ → Metal oxide (basic in nature) — e.g. 2Cu + O₂ → 2CuO
- Amphoteric oxides (react with both acids and bases): Al₂O₃, ZnO
- Non-metal + O₂ → Non-metal oxide (acidic in nature) — e.g. S + O₂ → SO₂
- Reactivity series (high to low): K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au
- Displacement reaction: a more reactive metal displaces a less reactive metal from its salt solution — e.g. Zn + CuSO₄ → ZnSO₄ + Cu
- Metal + dilute acid → Salt + H₂↑ (only for metals above hydrogen in the reactivity series)
- Ionic (electrovalent) compounds: formed by transfer of electrons between metal and non-metal; high melting/boiling points; conduct electricity in molten/aqueous state, not in solid state; generally soluble in water, insoluble in kerosene/petrol
- Metal extraction (reactive metals): concentration of ore → conversion to oxide (calcination/roasting) → reduction to metal → refining (often electrolytic refining)
- Electrolytic refining: impure metal = anode, pure metal strip = cathode, metal salt solution = electrolyte; pure metal deposits on cathode, impurities settle as anode mud
- Corrosion: gradual destruction of metal by reaction with air/moisture/chemicals (e.g. rusting of iron: Fe₂O₃.xH₂O)
- Preventing corrosion: painting, oiling/greasing, galvanising (zinc coating), alloying
- Alloys: homogeneous mixtures of two or more metals (or metal + non-metal) that improve properties — e.g. brass (Cu+Zn), bronze (Cu+Sn), stainless steel (Fe+Cr+Ni)
- Aqua regia: 3:1 mixture of concentrated HCl and concentrated HNO₃ — can dissolve gold and platinum
Related: Solutions | Extra Questions | Revision Notes | Formulas Handbook | Class 10 Science Book
