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Metals, Non-Metals, Ores and Alloys
3.1 Properties: Metals vs. Non-Metals
| Property | Metals | Non-Metals |
|---|---|---|
| State at RT | Mostly solid (except Hg — liquid) | Solid, liquid (Br), or gas |
| Lustre | Shiny | Dull (except iodine) |
| Conductivity | Good conductors (heat & electricity) | Poor conductors (except graphite) |
| Malleability | Malleable and ductile | Brittle |
| Electron tendency | Lose electrons (oxidation) | Gain electrons (reduction) |
| Oxides | Basic (e.g., Na₂O, CaO) | Acidic (e.g., SO₂, CO₂) |
| Examples | Fe, Cu, Al, Au, Ag | C, S, P, Cl, O, N |
Metalloids (semi-metals): Properties intermediate between metals and non-metals. Examples: Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb) — used as semiconductors in electronics.
3.2 Major Ores and their Metals
| Metal | Primary Ore | Formula | Major States in India |
|---|---|---|---|
| Iron (Fe) | Haematite | Fe₂O₃ | Jharkhand, Odisha, Chhattisgarh |
| Aluminium (Al) | Bauxite | Al₂O₃·2H₂O | Odisha, Andhra Pradesh, Jharkhand |
| Copper (Cu) | Chalcopyrite | CuFeS₂ | Rajasthan (Khetri), Jharkhand, MP |
| Zinc (Zn) | Sphalerite (Zinc blende) | ZnS | Rajasthan (Zawar, Rampura-Agucha) |
| Lead (Pb) | Galena | PbS | Rajasthan (Rampura-Agucha) |
| Manganese (Mn) | Pyrolusite | MnO₂ | Odisha, MP, Karnataka |
| Gold (Au) | Native gold, Calaverite | AuTe₂ | Karnataka (Kolar), Rajasthan |
Rajasthan's Mineral Significance: Rajasthan is India's largest producer of zinc-lead ores (Hindustan Zinc Ltd., Rampura-Agucha mine in Bhilwara district is the world's largest zinc mine by mined metal output). Khetri copper complex in Jhunjhunu is one of India's largest copper mines.
3.3 Alloys — Composition and Uses
| Alloy | Composition | Key Properties | Uses |
|---|---|---|---|
| Stainless Steel | Fe + Cr (10–11%) + Ni (1–2%) | Corrosion-resistant | Cutlery, surgical instruments, kitchen ware |
| Brass | Cu (70%) + Zn (30%) | Malleable, attractive colour | Musical instruments, taps, fittings |
| Bronze | Cu (90%) + Sn (10%) | Hard, corrosion-resistant | Statues, coins, bearings, bells |
| Duralumin | Al (94%) + Cu + Mg + Mn | Light, strong | Aircraft bodies, spacecraft |
| Solder | Pb (37%) + Sn (63%) | Low melting point | Electrical wiring joints |
| German Silver | Cu + Zn + Ni | White, corrosion-resistant | Silverware, jewellery |
| Steel | Fe + C (0.2–2%) | Strong, hardened | Construction, machinery |
| Cast Iron | Fe + C (2–4.5%) | Hard but brittle | Engine blocks, pipes |