Chapter 3 — Metals and Non-metals

Chapter 3 of the Class 10 Science NCERT textbook, "Metals and Non-metals", explains their physical and chemical properties, the reactivity series, extraction from ores, ionic compound formation, corrosion, and alloys.

• Telling metals from non-metals — Metals are lustrous, malleable, ductile, and good conductors, and form basic oxides, while non-metals are generally the opposite. A few exceptions, like conducting graphite and lustrous iodine, show the classification is based on overall behaviour.
• The reactivity series as an organising idea — Arranging metals from most to least reactive predicts their chemistry: a more reactive metal displaces a less reactive one from its compound, and reactivity determines whether a metal reacts with water, acids, or oxygen.
• Getting pure metals and protecting them — Extraction method follows reactivity — electrolysis for the most reactive, carbon reduction for moderate, heating for the least. Once obtained, metals are shielded from corrosion by galvanisation, painting, and alloying into materials like stainless steel.

1. 01Metals are lustrous, malleable, ductile, and good conductors of heat and electricity; most are solids at room temperature, with mercury being the only liquid metal.
2. 02Non-metals are generally poor conductors and non-malleable; exceptions include graphite (conducts electricity) and iodine (lustrous).
3. 03Metals react with oxygen to form basic oxides; amphoteric oxides like aluminium oxide (Al₂O₃) and zinc oxide react with both acids and bases.
4. 04The reactivity series ranks metals from most reactive (K, Na, Ca) to least reactive (Cu, Hg, Ag, Au); a more reactive metal displaces a less reactive one from its salt solution.
5. 05Metals high in the activity series (Na, Mg, Al) are extracted by electrolytic reduction; moderately reactive metals (Zn, Fe) are obtained by roasting/calcination followed by reduction with carbon.
6. 06Corrosion of iron (rusting) requires both water and oxygen; prevention methods include galvanisation, painting, and alloying (e.g., stainless steel with nickel and chromium).