Metals & Non-metals
Overview: Physical & Chemical properties, Reactivity Series, Ionic Bonding, Metallurgy.
1. Physical Properties
- Metals: Lustrous, Hard (except Na, K), Malleable, Ductile, Good conductors. Solid at RT (except Mercury).
- Non-metals: Dull (except Iodine), Brittle, Poor conductors (except Graphite). Solid/Gas (Bromine is liquid).
2. Chemical Properties
- Metal + Oxygen → Metal Oxide (Basic). Al2O3, ZnO are amphoteric.
- Metal + Water → Metal Oxide/Hydroxide + H2. (Na, K react violently).
- Metal + Dil Acid → Salt + H2.
- Reactivity Series: K > Na > Ca > ... > Au.
3. Ionic Bond
Formed by transfer of electrons from Metal to Non-metal.
Properties of Ionic Compounds: High MP/BP, Soluble in water, Conduct electricity in molten/aq state.
4. Metallurgy
- Roasting: Sulphide ores heated in excess air. (2ZnS + 3O2 → 2ZnO + 2SO2).
- Calcination: Carbonate ores heated in limited air. (ZnCO3 → ZnO + CO2).
- Thermite Reaction: Reduction using Aluminium (Fe2O3 + 2Al → 2Fe + Al2O3 + Heat). Used to join railway tracks.
NCERT In-Text Questions (Solved)
Page 40
Q1. Metal which is liquid at room temp?
Mercury.
Q2. Metal which can be cut with a knife?
Sodium and Potassium.
Q3. Best conductor of heat?
Silver.
Q4. Poor conductor of heat?
Lead and Mercury.
Q5. Explain Malleable and Ductile.
Malleable: Can be beaten into thin sheets (Gold, Silver).
Ductile: Can be drawn into thin wires (Gold is most ductile).
Ductile: Can be drawn into thin wires (Gold is most ductile).
Page 46
Q1. Why is sodium kept immersed in Kerosene oil?
Sodium is highly reactive. It reacts vigorously with oxygen and moisture in air and
catches fire. To prevent accidental fire, it is kept in kerosene.
Q2. Equations for Iron with steam and Calcium with water.
(i) 3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)
(ii) Ca(s) + 2H2O(l) → Ca(OH)2(aq) + H2(g)
(ii) Ca(s) + 2H2O(l) → Ca(OH)2(aq) + H2(g)
Q3. Reaction of A, B, C, D with solutions. Arrangement in reactivity.
(i) Most reactive: B (Displaces Iron).
(ii) B + CuSO4: Displacement reaction (Blue fades, Red-brown deposit).
(iii) Order: B > A > C > D.
(ii) B + CuSO4: Displacement reaction (Blue fades, Red-brown deposit).
(iii) Order: B > A > C > D.
Q4. Which gas when dilute HCl is added to reactive metal? Iron + H2SO4 eq.
Hydrogen gas.
Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g).
Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g).
Q5. Observation when Zinc is added to Iron(II) Sulphate?
Zinc is more reactive than Iron. It displaces Iron.
Green color of FeSO4 solution fades and greyish iron metal is deposited.
Green color of FeSO4 solution fades and greyish iron metal is deposited.
Page 49
Q1. Electron dot structure for Na, O, Mg.
Na has 1 valence electron (•).
O has 6 valence electrons (∶).
Mg has 2 valence electrons (:).
O has 6 valence electrons (∶).
Mg has 2 valence electrons (:).
Q2. Formation of Na2O and MgO.
Na2O: Two Na atoms transfer 1 electron each to one O atom. Structure:
[Na]+2 [O]2-.
MgO: One Mg atom transfers 2 electrons to one O atom. Structure: [Mg]2+ [O]2-.
MgO: One Mg atom transfers 2 electrons to one O atom. Structure: [Mg]2+ [O]2-.
Q3. Ions present in these compounds?
Na2O: Sodium ion (Na+), Oxide ion (O2-).
MgO: Magnesium ion (Mg2+), Oxide ion (O2-).
MgO: Magnesium ion (Mg2+), Oxide ion (O2-).
Page 53
Q1. Define Mineral, Ore, Gangue.
Mineral: Natural occurring elements/compounds in earth's crust.
Ore: Mineral from which metal can be extracted profitably.
Gangue: Impurities (sand, soil) present in ore.
Ore: Mineral from which metal can be extracted profitably.
Gangue: Impurities (sand, soil) present in ore.
Q2. Two metals found in free state.
Gold and Platinum (Least reactive).
Q3. Chemical process to obtain metal from oxide?
Reduction process (using Carbon, Coke, or reactive metals like Al). ZnO + C → Zn +
CO.
NCERT Exercise Questions
Complete solutions for Chapter 3 exercises.
Q1. Which of the following pairs will give displacement reaction?
(d) AgNO3 solution and Copper metal. Copper is more reactive than Silver, so
it displaces Silver.
Q2. Method for preventing iron frying pan from rusting?
(c) Applying a coating of zinc (Galvanization). Grease/Paint will burn off.
Q3. Element reacts with oxygen to give high melting point compound, soluble in
water. Element is?
(a) Calcium. CaO is soluble and forms Lime water.
Q4. Food cans coated with Tin not Zinc because:
(c) Zinc is more reactive than Tin. It might react with organic acids in food.
Q5. You are given a hammer, battery, bulb, wires, switch. How to distinguish
metal/non-metal?
(i) Hammer: Beat the sample. If it flattens into sheet (Malleable), it is Metal. If it
breaks (Brittle), it is Non-metal.
(ii) Circuit: Connect sample in circuit. If bulb glows, it conducts electricity (Metal). If not, Non-metal.
(ii) Circuit: Connect sample in circuit. If bulb glows, it conducts electricity (Metal). If not, Non-metal.
Q6. Amphoteric oxides? Examples.
Metal oxides which react with both acids and bases to produce salt and water.
Examples: Aluminium Oxide (Al2O3) and Zinc Oxide (ZnO).
Examples: Aluminium Oxide (Al2O3) and Zinc Oxide (ZnO).
Q7. Two metals displacing Hydrogen from dilute acid, two which don't.
Displace H2: Magnesium, Zinc (More reactive than H).
Don't displace H2: Copper, Silver (Less reactive than H).
Don't displace H2: Copper, Silver (Less reactive than H).
Q8. Electrolytic refining of metal M. Anode, Cathode, Electrolyte?
Anode: Impure metal M.
Cathode: Strip of pure metal M.
Electrolyte: Salt solution of metal M.
Cathode: Strip of pure metal M.
Electrolyte: Salt solution of metal M.
Q9. Pratyush burns sulphur using spatula. Collects gas. Action on litmus?
(i) Gas is Sulphur Dioxide (SO2).
Dry litmus: No action.
Moist Blue litmus: Turns Red (SO2 is acidic oxide).
(ii) Reaction: S + O2 → SO2.
SO2 + H2O → H2SO3 (Sulphurous acid).
Dry litmus: No action.
Moist Blue litmus: Turns Red (SO2 is acidic oxide).
(ii) Reaction: S + O2 → SO2.
SO2 + H2O → H2SO3 (Sulphurous acid).
Q10. Preventing rusting of iron?
1. Painting/Oiling: Cuts contact with moisture/air.
2. Galvanization: Coating with Zinc.
2. Galvanization: Coating with Zinc.
Q11. Oxides of non-metals type?
Acidic oxides (e.g., SO2, CO2) or Neutral oxides
(e.g., H2O, CO).
Q12. Reason for Platinum, Gold, Silver for jewelry?
They are least reactive (Native metals), do not corrode, and retain luster for a long time.
Q13. Sodium, K stored under oil?
To prevent reaction with oxygen/moisture and accidental fires.
Q14. Aluminium is reactive but used for cooking?
Aluminium forms a thin, stable protective layer of oxide (Al2O3) which prevents
further corrosion. Also, it is a good conductor of heat.
Q15. Carbonate and Sulphide ores converted to oxide?
Because it is easier to extract metal (reduce) from its oxide than from carbonate or sulphide.
Q16. Alloy definition and composition.
Homogeneous mixture of two or more metals (or metal + non-metal).
Brass: Copper + Zinc.
Bronze: Copper + Tin.
Solder: Lead + Tin.
Brass: Copper + Zinc.
Bronze: Copper + Tin.
Solder: Lead + Tin.
Key Reactions & Facts
Common ores, alloys, and properties.
Important Chemical Formulas
Cinnabar (Mercury Ore)
HgS
Zinc Blende
ZnS
Calamine
ZnCO3
Haematite (Iron Ore)
Fe2O3
Bauxite (Aluminium Ore)
Al2O3.2H2O
Rust
Fe2O3.xH2O
Sodium Aluminate
NaAlO2
50 Important Facts
1. Mercury is liquid at room temperature.
2. Bromine is a liquid non-metal.
3. Gallium and Caesium have very low melting points.
4. Alkali metals (Li, Na, K) are soft.
5. Na and K can be cut with a knife.
6. Diamond is the hardest natural substance.
7. Graphite is a non-metal but conducts electricity.
8. Iodine is a lustrous non-metal.
9. Metals form basic oxides.
10. Non-metals form acidic oxides.
11. Amphoteric oxides react with acid and base.
12. Examples of amphoteric: Al2O3, ZnO.
13. K and Na react vigorously with cold water.
14. Mg reacts with hot water.
15. Al, Fe, Zn react with steam only.
16. Au, Ag, Cu, Pb do not react with water.
17. Calcium floats on water (bubbles of H2 stick).
18. Magnesium also floats on hot water.
19. Aqua Regia dissolves Gold.
20. Aqua Regia is 3:1 mixture of Conc HCl and Conc
HNO3.
21. Reactivity Series: K > Na > Ca > Mg...
22. Hydrogen is placed in reactivity series despite
being non-metal.
23. Ionic compounds are solids.
24. Ionic compounds have high MP and BP.
25. Ionic compounds conduct electricity in solution.
26. Minerals: Elements/compounds found naturally in
earth crust.
27. Ores: Minerals from which metal is extracted
profitably.
28. Gangue: Impurities (sand/soil) in ore.
29. Roasting: Heating sulfide ore in excess air.
30. Calcination: Heating carbonate ore in limited
air.
31. Reduction used for metal oxides to metal.
32. Coke (Carbon) is a common reducing agent.
33. Thermite reaction is used to join railway
tracks.
34. Fe2O3 + 2Al -> 2Fe + Al2O3 + Heat.
35. Aluminium is used as reducing agent in Thermite
process.
36. Anode Mud: Impurities settled during
electrolysis.
37. Corrosion of Iron is called Rusting.
38. Galvanization: Coating Iron with Zinc.
39. Alloying improves properties of metals.
40. Brass: Copper + Zinc.
41. Bronze: Copper + Tin.
42. Solder: Lead + Tin (Low MP, used for welding).
43. Amalgam: Alloy containing Mercury.
44. Pure Gold is 24 carat (very soft).
45. Jewellery Gold is 22 carat (22 parts Gold + 2
parts Cu/Ag).
46. Steel: Iron + Carbon.
47. Stainless Steel: Iron + Nickel + Chromium.
48. Magnesium burns with dazzling white flame.
49. Copper becomes black (CuO) on heating.
50. Silver turns black due to Sulfur (Ag2S).
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