Ch 07: Metals, Non-metals & Metallurgy

⚙️ Chapter At a Glance

Ag (Silver)

Best Conductor

Au (Gold)

Most Ductile Metal

Al (8%)

Most Abundant Metal in Crust

Liquid Metal

Liquid Non-metal

📘 Metal vs Non-metal

Metals: Electropositive → lose electrons → form cations
Non-metals: Electronegative → accept electrons → form anions
Hydrogen is a non-metal with similarities to both alkali metals and halogens

⚡ Reactivity Series (Most → Least Reactive)

›

🔴 More Reactive (extracted by electrolysis) → 🟡 Medium → 🟢 Less Reactive (found free in nature)

🔩 Properties of Metals

Many metals are lustrous, malleable and ductile; hardness varies widely
Most ductile: Gold (Au), then Silver (Ag)
Good conductor of electricity and heat
Silver is the best ordinary bulk metallic conductor; mercury has unusually low conductivity among common metals. “Lead is lowest” is not universal.
Most freshly cut or polished metals are lustrous; tarnish/oxide layers can mask the shine
Many simple metal oxides are basic; amphoteric and acidic exceptions exist
Amphoteric oxides: Al₂O₃, ZnO, PbO

⭐ Important Metal Facts

Category	Metal
Strategic Metal	Titanium (Ti)
Liquid Metal	Mercury (Hg)
Highly Radioactive Alkali Metal	Francium (Fr)
Most Abundant in Earth's Crust	Aluminium (Al) — 8%
Densest Metal (ordinary conditions)	Osmium (Os)
Lightest Metal; very strong aqueous reducing agent	Lithium (Li)
Most Ductile	Gold (Au)
Best Conductor	Silver (Ag)
Liquid Non-metal	Bromine (Br)

Diseases from Excess Metal

Wilson disease is inherited and causes abnormal copper accumulation; it is not simply caused by excess copper intake
Excess Mercury (Hg) → Minamata Disease

No Reaction with O₂ or Water

Gold and platinum are especially resistant under ordinary conditions; Ag, Pb and Hg have condition-dependent reactions/tarnishing

🔥 Flame Colours of Metals

Golden Yellow

Purple / Lilac

Red Violet

Crimson Red

Apple Green

Red (Fireworks)

⚠️ Exam Trap — Flame Colours

Na (Sodium) = Golden Yellow flame (street lamp colour)
K (Potassium) = Purple/Lilac
Ba (Barium) = Apple Green (fireworks)
Sr (Strontium) = Red in fireworks | Li = Crimson Red

Metal	Key Uses
Na (Sodium)	Street lamps (yellow light)
Cu (Copper)	Wires, utensils, foil
Al (Aluminium)	Wire, space industry
Hg (Mercury)	Thermometer, tube lights
Mg (Magnesium)	Flash bulb making
Fe (Iron)	Steel industry
Cd (Cadmium)	Neutron absorber in reactor control rods (not a moderator)
Ba (Barium)	Green colour in fireworks
Sr (Strontium)	Red colour in fireworks

⚡ Reactivity Series — Full Detail

›

Activity Level	Metals	Extraction Method
Highly Active	K, Na, Ca, Mg, Al	Electrolysis (molten state)
Medium Active (Carbonate ore)	Zn, Fe, Pb, Cu	Calcination → Metal oxide → Reduction (Smelting)
Medium Active (Sulphide ore)	Zn, Fe, Pb, Cu	Roasting → Metal oxide → Reduction
Less Active	Ag, Au	Some occur native; recovery depends on ore and may involve leaching, reduction or refining

⚠️ Exam Trap — Reactivity

More reactive metal displaces less reactive metal from solution
Fe + CuSO₄ → FeSO₄ + Cu (Fe more reactive than Cu)
K, Na, Ca, Mg, Al extracted by electrolysis
Ag, Au found in native/free state in nature
H is placed between Pb and Cu in reactivity series

🪨 Important Ores of Metals

Metal	Important Ore	Formula
Aluminium (Al)	Bauxite (main ore)	Al₂O₃·xH₂O (variable hydration)
Aluminium (Al)	Cryolite / Corundum	Na₃AlF₆ / Al₂O₃
Copper (Cu)	Chalcopyrite (main ore)	CuFeS₂
Iron (Fe)	Haematite (main ore)	Fe₂O₃
	Magnetite	Fe₃O₄
Lead (Pb)	Galena (main ore)	PbS
Zinc (Zn)	Zincblende / Calamine	ZnS / ZnCO₃
Manganese (Mn)	Pyrolusite (main)	MnO₂
Silver (Ag)	Argentite	Ag₂S
Calcium (Ca)	Calcite	CaCO₃
Magnesium (Mg)	Magnesite / Dolomite	MgCO₃ / CaMg(CO₃)₂
Cadmium (Cd)	Greenockite	CdS

⚠️ Exam Trap — Ores

Aluminium main ore = Bauxite (Al₂O₃·xH₂O (variable hydration))
Copper main ore = Chalcopyrite (CuFeS₂) (also contains Fe)
Iron main ore = Haematite (Fe₂O₃); Magnetite = Fe₃O₄
Lead ore = Galena (PbS)
Pyrolusite (MnO₂) = main ore of Manganese (used in dry cells)
Mineral vs Ore: All ores are minerals but not all minerals are ores

🌿 Non-Metals

Accept electrons → form anions (electronegative)
Non-metal counts depend on classification of borderline elements; no universal fixed total of 22 applies
Bad conductor of electricity (Exception: Graphite = good conductor)
Hardest non-metal: Diamond
Liquid non-metal: Bromine (Br)
Many non-metal oxides are acidic; neutral oxides such as CO and NO are exceptions
Low melting and boiling points (mostly)
Not malleable, not shiny (mostly)

⚠️ Exam Trap — Non-metals

Graphite = non-metal but good conductor of electricity
Diamond = non-metal but hardest substance and very high MP
Bromine (Br) = only liquid non-metal at room temperature
Hydrogen is a non-metal; similarities to alkali metals/halogens do not make it both metal and non-metal

Metalloids (Semi-metals)

Have BOTH metallic and non-metallic properties

Present only in p-block
Metalloid lists vary; no universally fixed IUPAC count
Amphoteric oxides (react with both acid & base)
Boron fibres: aerospace composites; boron carbide (B₄C): hard armour material
Common metalloids: B, Si, Ge, As, Sb, Te; Po and At are borderline/classification-dependent

💨 Inert Gases (Noble Gases) — Group 18

Established noble gases are relatively unreactive: He has 1s² (duet), the others filled valence octets; compounds of some noble gases exist
Group 18 has 7 elements: He, Ne, Ar, Kr, Xe, Rn, Og. The six established light members are gases at ordinary conditions.

Gas	Key Uses
Helium (He)	Balloons, light aircraft (non-flammable); artificial respiration (divers); nuclear reactor coolant
Argon (Ar)	Welding; incandescent electric bulbs; tube lights (Hg vapour + Ar)
Neon (Ne)	Neon signs (advertising)
Xenon (Xe)	Photography flash tubes; "Stranger gas"

🔧 Alloys

📘 Definition

An alloy is a metallic material containing at least one metal and other element(s); it may be a solid solution, intermetallic or multiphase material

Brass

Cu 70% + Zn 30%

Utensils, wires, pipes, parts

Bronze

Cu 80% + Sn 20%

Utensils, statues (oldest alloy)

German Silver

Representative: Cu 60% + Zn 20% + Ni 20%; grade-dependent

Jewellery, utensils, statues

Solder

Sn 50% + Pb 50%

Metal plating, joining metals

Stainless Steel

18/8 stainless: Fe balance, ~18% Cr, ~8% Ni, low carbon

Blades, valves, surgical instruments

Amalgam

Any metal + Mercury (Hg)

Mercury-containing alloy; historically used in dental restorations. Ease of amalgamation depends on metal and surface conditions.

⚠️ Exam Trap — Alloys

Brass = Cu + Zn (NOT Cu + Sn) | Bronze = Cu + Sn
German Silver has NO silver — Cu + Zn + Ni
Stainless Steel: Cr (Chromium) gives rust resistance
Amalgam contains Hg; ease of formation varies with the metal and surface conditions
Solder = Sn + Pb (low melting point alloy — melts easily)

💧 Hydrogen & Water

Hydrogen (H₂)

Discoverer: Henry Cavendish (1766)

Atomic mass: 1.008 | Symbol: H
Electronic config: 1s¹
Neutral protium (¹H): one proton, one electron, no neutron; other isotopes have neutrons
Diatomic molecule (H₂)
Hydrogen: roughly three-quarters of ordinary cosmic matter by mass
Molecular H₂: trace atmospheric gas, approximately 0.00005%
Hydrogen abundance depends on the reservoir; distinguish cosmic matter, crust, oceans and atmosphere
Uses: Rocket fuel, NH₃ synthesis, fuel cell

Water (H₂O)

Universal Solvent

pH = 7 (neutral, pure)
Max density, min volume at 4°C
Bond angle H–O–H = 104.5°
Ice ~0.917 g/cm³ near 0°C; liquid water ~0.997 g/cm³ at 25°C; vapour density needs temperature and pressure
Colourless, tasteless, odourless

💧 Hard Water vs Soft Water

Hard Water

Contains dissolved Ca and Mg salts (sulphate, carbonate, chloride). No foam/lather with soap.

Temporary hardness: due to bicarbonates of Ca, Mg. Removed by Boiling or Clark's Method
Permanent hardness: due to sulphates & chlorides. Removed by Washing Soda, Calgon, Ion-exchange, Resin method

Soft Water

Free from Ca and Mg salts. Forms good lather/foam with soap. Rainwater is naturally soft water.

🧪 Heavy Water (D₂O) & H₂O₂

Heavy Water (D₂O)

D₂O is deuterium oxide, denser than ordinary water. Urey discovered deuterium (1931–32); Lewis and coworkers obtained pure heavy water (1933).

Nuclear-reactor moderator (heavy water, D₂O)
Studying mechanism of chemical reactions
Making deuterium compounds (CD₄, D₂SO₄)

Hydrogen Peroxide (H₂O₂)

Discovered by Thénard (1818). Also called Oxygenated Water. Acts as both oxidant and reducing agent.

Industrial bleaching and oxidation
Hair bleaching & antiseptic
Rocket fuel
Making hydroquinone & tartaric acid

⚠️ Exam Trap — Water

Water max density at 4°C (NOT 0°C)
H–O–H bond angle = 104.5°
Temporary hardness removed by Boiling; Permanent by Washing Soda
Heavy water = D₂O; distinguish Urey’s deuterium discovery (1931–32) from Lewis’s pure D₂O preparation (1933)
Heavy water = nuclear reactor moderator
H₂O₂ discovered by Thénard (1818); is both oxidant and reducer

🏭 Metallurgy — Extraction Process

📘 Metallurgy

Metallurgy: ore → concentration → conversion to a suitable compound → extraction/reduction → crude metal → refining; not every route must pass through an oxide

Ore

→

Concentration of Ore

→

Suitable compound (often oxide)

→

Reduction (Smelting)

→

Crude Metal

→

Refining

📋 Key Metallurgy Terms

Term	Definition	Key Details
Mineral	Naturally occurring inorganic solid with definite chemical composition & crystalline structure	Not all minerals are ores
Ore	Mineral from which metal can be extracted easily and economically	All ores are minerals
Flux	Converts infusible impurities into fusible slag	e.g., CaO (basic flux) or SiO₂ (acid flux)
Slag	Fusible waste formed by Flux + acidic/basic impurities	Examples of slag: CaSiO₃, FeSiO₃ (process-dependent); SiO₂/Al₂O₃ may be gangue constituents
Calcination	Heating concentrated ore below melting point in absence/limited air	Removes volatile impurities; for carbonate ores
Roasting	Heating concentrated ore in excess air (reverberatory furnace)	For sulphide ores; oxidises impurities
Distillation	Purification method for low boiling metals	Zn, Cd, Hg
Liquation	Purification of low melting point metals	Sn, Pb and Bi (classic liquation examples)

⚠️ Exam Trap — Metallurgy

Calcination = absence of air (carbonate ores); Roasting = excess of air (sulphide ores)
K, Na, Ca, Mg, Al extracted by Electrolysis (very reactive)
Ag/Au are low-reactivity metals; native occurrence does not imply universal extraction by simple heating
Mineral ≠ Ore: Ore must be economically extractable
Flux converts gangue into slag (fusible, removable)
Distillation: Zn, Cd, Hg; liquation: Sn, Pb, Bi melted away from higher-melting impurities

🎯 High-Yield Exam Points

Silver: highest ordinary bulk metallic conductivity; mercury is a relatively poor metallic conductor
Most ductile = Gold (Au); Most abundant metal = Al (8% crust)
Liquid metal = Mercury (Hg); Lightest metal = Li
Osmium: commonly cited densest metal (~22.57 g/cm³); titanium: strategic aerospace/defence metal
Francium is highly radioactive; it is commonly listed as solid at 25°C, not reliably as a liquid metal
Common amphoteric oxides: Al₂O₃, ZnO and PbO
Wilson's Disease = excess Copper; Minamata = excess Mercury
Reactivity series: K>Na>Ca>Mg>Al>Zn>Fe>Pb>H>Cu>Hg>Ag>Au
Na flame = Golden Yellow; K = Purple; Ba = Apple Green; Li/Sr = Red
Au and Pt are especially resistant under ordinary conditions; do not assign this absolute rule to Ag, Pb and Hg
Bauxite (Al₂O₃·xH₂O (variable hydration)) = main ore of Al | Haematite (Fe₂O₃) = main ore of Fe
Chalcopyrite (CuFeS₂) = main ore of Cu | Galena (PbS) = main ore of Pb
Graphite = non-metal but good conductor; Diamond = hardest non-metal
Bromine = only liquid non-metal
Brass = Cu+Zn | Bronze = Cu+Sn | German Silver = Cu+Zn+Ni (NO Ag)
Stainless Steel: Cr gives rust resistance
Amalgam is a mercury-containing alloy; avoid absolute amalgamation rules without conditions
Group 18: He, Ne, Ar, Kr, Xe, Rn, Og (7 elements); He–Rn are the familiar six gases
He = balloons, nuclear coolant; Ar = welding, bulbs; Xe = photography flash
Hydrogen: Cavendish (1766); ~75% of ordinary cosmic matter by mass; H₂ ~0.00005% of air
Water max density at 4°C; bond angle = 104.5°
Temp hardness removed by boiling; Permanent by Washing Soda
D₂O: moderator; Urey: deuterium (1931–32), Lewis and coworkers: pure heavy water (1933)
H₂O₂: Thénard (1818); both oxidant and reducer
Calcination = no air; Roasting = excess air; Both → metal oxide

📋 Alloy Quick Reference

Alloy	Composition	Use
Brass	Cu 70% + Zn 30%	Utensils, wires
Bronze	Cu 80% + Sn 20%	Statues
German Silver	Cu+Zn+Ni	Jewellery
Solder	Sn 50% + Pb 50%	Plating
Stainless Steel	Fe+Cr+Ni+C	Surgical

⚠️ Most Common Exam Traps

Brass = Cu+Zn (NOT Cu+Sn)
German Silver has NO silver
Graphite = non-metal but conducts electricity
Water densest at 4°C (NOT 0°C)
H₂O₂ = both oxidant AND reducer
An amalgam contains mercury; formation depends on metal and surface conditions
Temporary hardness removed by Boiling; permanent by Washing Soda
Calcination = absent/limited air; Roasting = excess air
Hydrogen is the most abundant element in ordinary cosmic matter and is a non-metal; Al is the most abundant crustal metal
Minamata = Mercury | Wilson's = Copper

⚙️ Metals, Non-metals & Metallurgy