Metals & Non-Metals
Key Concepts
| # | Concept | Explanation |
|---|---|---|
| 1 | Metallic Lustre | Metals shine when cut/ polished because free electrons reflect light. |
| 2 | Malleability & Ductility | Metals can be beaten into sheets (malleable) & drawn into wires (ductile) due to non-directional metallic bonding. |
| 3 | Conductivity | Metals conduct heat & electricity via delocalised electrons; non-metals are insulators (except graphite). |
| 4 | Ionisation & Valency | Metals lose e⁻ → cations (+), valency = group no.; non-metals gain e⁻ → anions (–), valency = 8 – group no. |
| 5 | Reactivity Series | K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au; higher metal displaces lower from salt solution. |
| 6 | Amphoteric Oxides | Al₂O₃, ZnO react with both acid & base → salt + water. |
| 7 | Alloy | Solid solution of metals (or metal + non-metal); e.g. brass (Cu-Zn), stainless steel (Fe-Cr-Ni). |
| 8 | Occurrence | Reactive metals (Na, K) exist as chlorides/carbonates; noble metals (Au, Ag) occur native. |
15 Practice MCQs
-
Which metal is liquid at room temperature? A. Ga B. Hg C. Cs D. Fr
Answer: B
Mercury (Hg) is the only metal liquid at 25 °C.
Trick: “Hg = High-grade liquid metal.”
Tag: Physical state -
The oxide of which element turns red litmus blue? A. Sulphur B. Carbon C. Magnesium D. Phosphorus
Answer: C
MgO is basic; basic oxides turn red litmus blue.
Trick: “Metal-oxide = Basic.”
Tag: Nature of oxides -
Aluminium is obtained by electrolysis of which ore? A. Bauxite B. Haematite C. Magnetite D. Copper pyrites
Answer: A
Bauxite (Al₂O₃·2H₂O) → Hall-Héroult process.
Trick: “Alu = Baux-ite.”
Tag: Extraction -
Which non-metal conducts electricity? A. Diamond B. Sulphur C. Graphite D. Phosphorus
Answer: C
Graphite has delocalised electrons between layers.
Trick: “G for Graphite & Good conductor.”
Tag: Conductivity exception -
Iron is galvanised by coating with— A. Sn B. Zn C. Cu D. Cr
Answer: B
Zinc layer protects Fe sacrificially.
Trick: “Galva-Zn-c.”
Tag: Corrosion prevention -
The reaction 2Pb + O₂ → 2PbO is an example of— A. Reduction B. Oxidation C. Displacement D. Decomposition
Answer: B
Pb gains oxygen → oxidised.
Trick: “Oxygen added = Oxidation.”
Tag: Redox -
Which alloy contains Cu & Ni? A. Bronze B. Brass C. Constantan D. Solder
Answer: C
Constantan (Cu 55 % + Ni 45 %).
Trick: “Con-stan-tan → Cu-Ni.”
Tag: Alloys -
Most abundant metal in Earth’s crust is— A. Fe B. Al C. Ca D. Na
Answer: B
Al ≈ 8 % by weight.
Trick: “Alu-minimum space, maximum share.”
Tag: Abundance -
Which metal forms amphoteric oxide? A. Na B. Cu C. Zn D. Au
Answer: C
ZnO reacts with both HCl & NaOH.
Trick: “Zn = Zero preference (acid/base).”
Tag: Amphoteric -
Thermite mixture contains— A. Fe₂O₃ + Al B. CuO + Zn C. Al₂O₃ + Mg D. PbO + C
Answer: A
Fe₂O₃ + Al → Fe + Al₂O₃ + heat (welding).
Trick: “Fe-Al = Fire-welding.”
Tag: Thermite reaction -
Which gas is released when Zn reacts with dil. H₂SO₄? A. O₂ B. SO₂ C. H₂ D. CO₂
Answer: C
Zn + H₂SO₄ → ZnSO₄ + H₂↑
Trick: “Metal + Acid → Salt + H₂.”
Tag: Metal-acid reaction -
Stainless steel contains— A. Fe, Cr, Ni B. Fe, C, Mn C. Cu, Zn D. Fe, Cu, Sn
Answer: A
Cr (≈18 %) + Ni (≈8 %) prevent rusting.
Trick: “SS = Strong & Shiny → Cr-Ni.”
Tag: Alloys -
Non-metal used to vulcanise rubber is— A. P B. S C. Cl D. I
Answer: B
Sulphur cross-links rubber chains.
Trick: “S = Soft-rubber Stiffener.”
Tag: Non-metal use -
Which metal is stored under kerosene? A. Ca B. Mg C. Na D. Al
Answer: C
Na reacts violently with moisture.
Trick: “Na = Kero-sene-guard.”
Tag: Storage -
In the reactivity series, which metal can displace copper from CuSO₄ solution? A. Ag B. Au C. Fe D. Hg
Answer: C
Fe is above Cu → displaces it.
Trick: “Higher kicks Lower.”
Tag: Displacement
Speed Tricks
| Situation | Shortcut | Example |
|---|---|---|
| Basic vs Acidic oxide | “Metal-oxide = Basic, Non-metal-oxide = Acidic” | CO₂ acidic, CaO basic |
| Liquid metals at 30 °C | “Hg Ga Cs” – remember Hg is only pure liquid, Ga & Cs melt in hand | |
| Conductivity exception | “Graphite is the only non-metal conductor” – G & Good | |
| Displacement rule | “Upper metal kicks lower metal out of salt solution” | Zn + CuSO₄ → ZnSO₄ + Cu |
| Alloy composition | “Bronze = Cu-Sn, Brass = Cu-Zn, Stainless = Fe-Cr-Ni” – B-Sn, B-Zn, SS-CrNi |
Quick Revision
| Point | Detail |
|---|---|
| 1 | Metals have 1-3 valence electrons, form cations. |
| 2 | Non-metals have 4-7 valence electrons, form anions. |
| 3 | Al is extracted from bauxite by Hall-Héroult process. |
| 4 | Iron is obtained in blast furnace; limestone removes impurities as slag. |
| 5 | Copper is refined by electrolytic refining; pure Cu deposits at cathode. |
| 6 | Galvanisation = Zn coating; Tin-plating = Sn coating. |
| 7 | Thermite reaction: Fe₂O₃ + Al → Fe + Al₂O₃ (used in rail welding). |
| 8 | Amphoteric oxides: Al₂O₃, ZnO, PbO. |
| 9 | Aqua-regia (3 HCl : 1 HNO₃) dissolves Au & Pt. |
| 10 | Mercury & Al compounds cause water pollution called “heavy-metal pollution”. |
BETA
