Metals and Non-metals · Class 10 Science: quick revision, 60 bites

The Metal Checklist

The seven signs of a metal

Takeaway. Shine, ring, flatten, stretch, conduct — the metallic signature.

Malleable vs Ductile

Two words, two shapes

Takeaway. Mould into sheets; Draw into wires.

Non-metal Properties

The opposite team

Takeaway. Dull, brittle, silent, insulating — the non-metal profile.

The Exceptions Table

Where examiners hunt

Takeaway. Seven exceptions answer most tricky MCQs of this topic.

Best and Worst Conductors

Medal winners of conduction

Best conductors of heat and electricity: **silver first, copper second** (copper wins wiring on price). Relatively poor among metals: **lead and mercury** — lead is even used where poor conduction is fine.

Takeaway. Silver > copper at the top; lead and mercury at the bottom.

Vark — Malleability on Dessert

Sweet-shop metallurgy

Takeaway. Foils are malleability made visible (and edible).

A Wire Is a Metal-Non-metal Sandwich

Why the wire and its cover differ

The copper core uses metal ductility and conduction; the plastic/rubber sheath uses non-metal insulation. One household object deliberately pairs the two classes' opposite properties.

Takeaway. Conductor inside, insulator outside — both classes at work.

Cutting Sodium

The knife test

Takeaway. Sodium: soft enough to cut, reactive enough to dull instantly.

Diamond and Graphite — Both Carbon

One element, two personalities

Takeaway. Same carbon atoms, different arrangements — wildly different properties.

Physical Tests Are Only Hints

The classification trap

Takeaway. Judge elements by their chemistry, not their looks.

Matching Metal to Use

Property-shopping for jobs

Takeaway. Every use is a property wearing work clothes.

Gallium's Party Trick

The vanishing spoon

Gallium melts at about 30 °C. A gallium spoon stirred into hot tea softens, bends and melts away — a metal defeated by a warm drink. Caesium behaves similarly.

Takeaway. Some metals melt at body heat — exceptions make chemistry fun.

Board Favourites

The four reliable questions

Takeaway. The exceptions ARE the exam questions here.

Melting Point Extremes

Extremes of melting

Highest melting element: **tungsten** (~3422 °C) — the bulb-filament metal. Among common metals iron melts at ~1538 °C, while the exceptions Na/K/Ga melt below 100 °C. Non-metals are generally low-melting — except **diamond**, which defies the class.

Takeaway. Tungsten tops the chart; diamond defends the non-metals.

Memory Pack

Whole topic in three lines

Takeaway. Three lines, all properties and exceptions.

Metals + Oxygen

Burning through the series

Takeaway. Same reaction, wildly different vigour — the first glimpse of the series.

Amphoteric Oxides (Al₂O₃, ZnO)

The oxides that swing both ways

Takeaway. AZ — Aluminium and Zinc oxides fight on both fronts.

Metals + Water

The temperature ladder

Takeaway. Cold → hot → steam → never: the water test ranks the metals.

Why Calcium (and Mg) Float

The dancing pebble

Takeaway. Sticking H₂ bubbles are the flotation devices.

Metals + Dilute Acids

The hydrogen gate

Takeaway. Above H reacts; below H watches.

The Nitric Acid Exception

The acid that breaks the rule

Takeaway. HNO₃ eats the hydrogen it would have released.

Aqua Regia

Royal water

No single acid touches gold; only the royal mixture does — hence the royal name.

Takeaway. 3 HCl : 1 HNO₃ — the only solvent of gold.

Displacement Builds the Series

The experiment that ranks them all

A metal placed in a LESS reactive metal's salt solution takes over: Zn + CuSO₄ → ZnSO₄ + Cu; Fe + CuSO₄ → FeSO₄ + Cu. The reverse never happens. Testing metals pairwise this way produces the full ranking — the **reactivity series**.

Takeaway. Who displaces whom = the experimental ladder of metals.

The Reactivity Series

The ladder itself

**K > Na > Ca > Mg > Al > Zn > Fe > Pb > (H) > Cu > Hg > Ag > Au**

Takeaway. Thirteen members, three bands — learn it cold.

Aluminium's Oxide Armour and Anodising

Reactive yet rust-proof

Aluminium reacts instantly with air — and that's exactly what saves it: the thin, tough **Al₂O₃ layer** seals the surface from further attack. **Anodising** thickens this armour electrolytically (the object is the ANODE in dilute H₂SO₄), giving corrosion-proof, even dyeable finishes.

Takeaway. Aluminium's reactivity builds its own shield; anodising upgrades it.

Worked: Will It React?

Predict before you dip

Takeaway. Check the ladder first — higher displaces lower, never the reverse.

Testing Gold with Acids

The jeweller's acid bench

Takeaway. Nobility is testable — acids expose the impostors.

Answer-Check Before Writing

The three classic slips

Takeaway. Check the series and the acid before writing any product.

Board Favourites

The reliable five

Takeaway. Five staples cover most of this topic's marks.

Memory Pack

Whole topic in three lines

Takeaway. Three lines, the whole chemical-property map.

Why Atoms React: the Octet

The universal motive

Atoms react to achieve the **stable, complete outer shell** of the nearest noble gas — usually 8 electrons (the octet). Noble gases don't react because they already have it. Losing, gaining or sharing electrons are just three roads to the same destination.

Takeaway. Every bond is an octet quest.

Metals Lose, Non-metals Gain

Givers and gainers

Takeaway. Metal gives, non-metal takes — ions are born.

NaCl, Step by Step

The one-electron trade

Takeaway. One perfect trade, two happy octets, one strong bond.

Ionic (Electrovalent) Bond

The bond, defined

Takeaway. Transfer makes ions; attraction makes the bond.

MgCl₂ and MgO

When two electrons move

Mg (2,8,2) must lose TWO electrons. With chlorine (takes one each): **two Cl atoms** are needed → **MgCl₂** (Mg²⁺ + 2Cl⁻). With oxygen (2,6 — wants two): one O takes both → **MgO** (Mg²⁺O²⁻).

Takeaway. Count the electrons moved — the formula follows automatically.

The Giant Lattice

No molecules here

Each ion attracts ALL its opposite neighbours, so ionic compounds build a **repeating 3-D crystal lattice** — alternating + and − in every direction. 'NaCl' is a ratio, not a molecule. Salt's cubic crystals are the lattice's geometry grown large.

Takeaway. Ionic compounds are cities of ions, not couples.

Four Signature Properties

The exam's favourite property list

Takeaway. Hard, high-melting, water-loving, fluid-conducting.

Why Conduction Needs Melting or Dissolving

The rule with a reason

A current is MOVING charge. In the solid, the ions are charged but **locked** in lattice positions — no movement, no current. Melt the crystal or dissolve it in water and the ions **break free** — mobile charges, current flows.

Takeaway. Ions must be free to move for conduction.

Why Ionic Crystals Are Brittle

Hard yet crackable

Strike the crystal and a layer of ions shifts slightly — suddenly + faces + and − faces −. The massive **repulsion** between like charges splits the crystal along that plane. Hardness and brittleness come from the same lattice.

Takeaway. One layer-slip turns attraction into repulsion — crack.

High Melting Points — the Evidence

The flame that fails

NaCl melts at **1074 K (801 °C)** — beyond a kitchen flame. Breaking the attractions of billions of ion pairs at once demands that much energy. High melting/boiling points are the lattice's strength written in numbers.

Takeaway. Strong bonds = big energy bills to melt.

Salt in Water vs Salt in Oil

Dinner-table chemistry

Takeaway. Water dismantles lattices; oils can't.

Worked: Calcium + Chlorine

Predict a new formula

Takeaway. Electron bookkeeping writes the formula for you.

Na the Metal vs Na⁺ the Ion

Same element, new personality

Sodium metal explodes in water; the Na⁺ in your salt shaker is perfectly calm. Losing one electron gives sodium a stable noble-gas shell — and an entirely different, safe chemistry. Ions are NOT small pieces of their metals.

Takeaway. An ion is a different chemical species from its atom.

Board Favourites

The four bankers

Takeaway. Formation diagrams + the conduction reason = the marks.

Memory Pack

Whole topic in three lines

Takeaway. Three lines, the whole ionic story.

Mineral, Ore, Gangue

Rock, treasure and trash

Takeaway. All ores are minerals; only profitable minerals are ores.

Three Zones, Three Methods

The series commands the factory

Takeaway. Reactivity decides the extraction bill.

Roasting vs Calcination

The twin heating steps

Takeaway. Roast the sulphide in the open; calcine the carbonate under cover.

Carbon Reduction

Coke, the oxygen thief

Cheap coke pulls the oxygen from middle-zone oxides — the workhorse of iron, zinc and lead production.

Takeaway. Middle-zone oxides surrender their oxygen to carbon.

The Thermite Reaction

A furnace in a crucible

Takeaway. Aluminium's hunger for oxygen melts iron on demand.

Mercury from Cinnabar

The bottom zone's shortcut

Cinnabar (HgS) heated in air first becomes the oxide, which further heating decomposes to the metal itself: 2HgS + 3O₂ → 2HgO + 2SO₂; then 2HgO → 2Hg + O₂. **Heat alone is enough** — the privilege of low reactivity.

Takeaway. Bottom-zone compounds fall apart with mere heating.

Electrolysis for the Top Zone

Where carbon fails

Sodium, magnesium, calcium and aluminium hold their oxygen (and chlorine) more tightly than carbon can pull — so their oxides resist carbon completely. Their molten compounds are split by ELECTRIC CURRENT: sodium from molten NaCl, aluminium from molten Al₂O₃ — the **metal always deposits at the cathode**.

Takeaway. Only current can free the top metals; cathode collects them.

Electrolytic Refining of Copper

The final polish

Takeaway. Impure anode shrinks, pure cathode grows, treasure sinks.

What an Alloy Is

Metal teamwork

Takeaway. Mix metals, upgrade properties — at a small conductivity cost.

The Alloy Gallery

The table exams lift directly

Takeaway. Six alloys, six compositions — memorise the pairs.

Brass vs Bronze vs Solder

The Zn-Sn mix-up

Takeaway. BraZ-Zinc, BronTin, Solder = Pb+Sn.

Iron Needs Carbon, Gold Needs Copper

Why nothing pure gets used

Takeaway. A pinch of alloying turns soft metals into working materials.

The Iron Pillar of Delhi

1600 years, zero rust

Standing since ~400 CE, the Delhi Iron Pillar has barely rusted — a tribute to ancient Indian metallurgists whose forging created a protective phosphate-rich surface layer. Corrosion resistance was engineered here a millennium before stainless steel.

Takeaway. India's ancient metallurgy solved corrosion before chemistry named it.

Board Favourites

The reliable five

Takeaway. Five staples carry the extraction topic's marks.

Memory Pack

Whole topic in three lines

Takeaway. Three lines, the whole metallurgy map.