Class 10 Science – Metals & Non‑metals
Quick Revision Sheet (English)
1. Basic Definitions
| Term | Definition |
|---|
| Metal | An element that is shiny, malleable, ductile, good conductor of heat & electricity, and usually forms cations (positive ions) in reactions. |
| Non‑metal | An element that is dull, brittle, poor conductor of heat & electricity, and usually forms anions (negative ions) or covalent compounds. |
| Alloy | A mixture of two or more metals, or a metal with a non‑metal, having metallic properties (e.g., brass = Cu + Zn). |
| Corrosion | Gradual destruction of a metal by reaction with its environment (most common: rusting of iron). |
| Oxidation | Loss of electrons / gain of oxygen / loss of hydrogen. |
| Reduction | Gain of electrons / loss of oxygen / gain of hydrogen. |
| Displacement Reaction | A more reactive metal displaces a less reactive metal from its salt solution. |
| Reactivity Series | Order of metals from most to least reactive (used to predict displacement & extraction). |
2. Physical Properties (Quick Comparison)
| Property | Metals | Non‑metals |
|---|
| Appearance | Shiny (metallic luster) | Dull, matte |
| State at RT | Mostly solid (except Hg, Br) | Solid, liquid, or gas |
| Malleability | ✔️ (can be hammered) | ✖️ (brittle) |
| Ductility | ✔️ (can be drawn into wires) | ✖️ |
| Conductivity (heat & electricity) | ✔️ (good) | ✖️ (poor) |
| Density | Generally high | Generally low |
| Ion formed in reactions | Cation (e⁺) | Anion (e⁻) or covalent |
3. Chemical Reactivity & Key Reactions
3.1 General Reaction Patterns
| Reaction Type | General Equation | Example |
|---|
| Metal + Oxygen (combustion) | M + O₂ → MO (or 2M + O₂ → 2MO) | 2Mg + O₂ → 2MgO |
| Metal + Water (cold) | M + H₂O → M⁺OH + H₂ (only very reactive metals) | 2Na + 2H₂O → 2NaOH + H₂ |
| Metal + Water (hot/steam) | M + H₂O → MO + H₂ (less reactive) | Ca + H₂O → CaO + H₂ |
| Metal + Acid | M + HX → MX + H₂ | Zn + 2HCl → ZnCl₂ + H₂ |
| Metal + Non‑metal (direct synthesis) | M + X₂ → MX₂ | 2Al + 3Cl₂ → 2AlCl₃ |
| Displacement (single‑replacement) | More reactive M + MX → M₂X + M | CuSO₄ + Zn → ZnSO₄ + Cu |
| Corrosion (rusting of iron) | 4Fe + 3O₂ + 6H₂O → 4Fe(OH)₃ → 2Fe₂O₃·3H₂O (simplified: 4Fe + 3O₂ → 2Fe₂O₃) | |
3.2 Reactivity Series (most → least reactive)
K > Na > Ca > Mg > Al > Zn > Fe > Ni > Sn > Pb > (H) > Cu > Ag > Au > Pt
Any metal above another in the series can displace the lower one from its compound.
4. Extraction of Metals
| Method | When Used | Representative Reaction |
|---|
| Thermal reduction (using carbon) | Metals with high affinity for oxygen (e.g., Fe) | Fe₂O₃ + 3C → 2Fe + 3CO |
| Electro‑reduction (electrolysis) | Metals with very high melting points (e.g., Al, Na) | 2Al₂O₃ → 4Al + 3O₂ (Hall‑Héroult process) |
| Distillation | Very reactive metals that form volatile chlorides (e.g., Na) | 2NaCl → 2Na (g) + Cl₂ (g) (followed by condensation) |
| Hydrometallurgy (leaching) | Low‑grade ores | Cu₂S + O₂ → 2Cu + SO₂ (followed by leaching) |
5. Important Formulas & Equations
| Concept | Formula | Meaning |
|---|
| Molar mass (M) | M = (mass of element in g) / (number of moles) | Used for stoichiometric calculations. |
| Percentage composition | % by mass = (mass of element in compound / total mass) × 100 | Helps identify compounds. |
| Corrosion rate (simplified) | Rate = (mass loss per unit area) / time | Expressed in mg cm⁻² day⁻¹. |
| Electro‑chemical equivalent | E = (Molar mass) / (n × F) | n = electrons transferred, F = Faraday’s constant (96 485 C mol⁻¹). |
| Law of Conservation of Mass | Mass of reactants = Mass of products | Applies to all chemical reactions. |
| Law of Definite Proportions | A given compound always contains the same proportion of elements by mass. | Basis for formula writing. |
6. Common Uses (Quick Reference)
| Category | Examples |
|---|
| Metals | Iron (Fe) – construction, tools; Copper (Cu) – electrical wiring; Aluminium (Al) – cans, aircraft; Gold (Au) – jewellery, electronics. |
| Non‑metals | Carbon (C) – fuels, plastics; Sulphur (S) – fertilizers, matches; Oxygen (O₂) – respiration, steel making; Nitrogen (N₂) – fertilizers (NH₃). |
| Alloys | Brass (Cu+Zn) – musical instruments; Bronze (Cu+Sn) – statues; Stainless steel (Fe+Cr+Ni) – cutlery, surgical tools. |
7. Quick Checklist for Exams
- Define metal, non‑metal, alloy, corrosion, oxidation, reduction.
- State the reactivity series and use it to predict:
- Which metal will displace another?
- Which metals react with water/acid?
- Write balanced equations for:
- Metal + oxygen, metal + water (cold & hot), metal + acid.
- Displacement reactions (e.g.,
Zn + CuSO₄).
- Corrosion of iron.
- Identify extraction method for a given metal (thermal reduction, electrolysis, etc.).
- Recall physical properties table (malleable, ductile, conductor, etc.).
- Remember key formulas: percentage composition, corrosion rate, electro‑chemical equivalent.
Keep this sheet handy – it covers all the essential definitions, laws, reactions, and formulas you need for the Metals & Non‑metals chapter!