Metals and Non-metals

Comprehensive Class 10 Study Guide | 2025-26 Edition

1. Physical Properties of Metals
2. Physical Properties of Non-metals
3. Chemical Properties of Metals
4. Amphoteric Oxides
5. Reaction with Water & Acids
6. Reactivity Series
7. Ionic Compounds (Bonding)
8. Extraction of Metals
9. Refining of Metals
10. Corrosion & Prevention

1. Physical Properties

Metals and non-metals can be identified based on their physical characteristics. In examinations, direct comparison questions are very common.

Properties of Metals:

Malleability: Metals can be beaten into thin sheets. Gold and Silver are the most malleable.
Ductility: The ability to be drawn into wires. 1 gram of gold can produce a 2km long wire.
Sonority: They produce a ringing sound when struck.
Conductivity: They are excellent conductors. Exception: Lead and Mercury are poor conductors.

Important Exceptions:

Remember for MCQs:

Mercury is the only metal liquid at room temperature.
Sodium, Lithium, and Potassium are so soft they can be cut with a knife.
Iodine is a non-metal but is lustrous (shiny).
Diamond (Carbon) is the hardest natural substance.

2. Chemical Properties of Metals

The chemical behavior of a metal depends on its position in the reactivity series.

A. Reaction with Oxygen

Almost all metals combine with oxygen to form metal oxides. These are generally basic.

2Cu + O₂ → 2CuO (Copper Oxide - Black)

Amphoteric Oxides:

Oxides like Aluminium Oxide (Al₂O₃) and Zinc Oxide (ZnO) are special. They react with both acids and bases to produce salt and water.

Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O (Acidic reaction)
Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O (Basic reaction)

B. Reaction with Water

The intensity of reaction depends on reactivity:

Condition	Metals
Cold Water	K, Na, Ca (Violent)
Hot Water	Mg
Steam Only	Al, Fe, Zn
No Reaction	Pb, Cu, Ag, Au

3. Reactivity Series & Displacement

The reactivity series is a list of metals arranged in decreasing order of their chemical activity.

Displacement Reaction:

A more reactive metal will push out a less reactive metal from its salt solution.

Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s)

In this case, the blue color of Copper Sulphate fades as Iron is more reactive than Copper.

4. Bonding: Ionic Compounds

Ionic compounds are formed when electrons are transferred from a metal to a non-metal.

Key Characteristics:

High Melting Points: Due to strong electrostatic forces between ions.
Conduction: They conduct electricity only in molten or aqueous states (where ions are free to move).
Solubility: Usually soluble in water but insoluble in organic solvents like petrol.

5. Extraction of Metals (Metallurgy)

Metallurgy is the process of extracting pure metal from its ore. It involves three main steps:

Step 1: Enrichment of Ore

Removal of impurities like soil/sand (called Gangue) from the ore.

Step 2: Reduction

Roasting: Heating sulphide ores in the presence of excess air.
Calcination: Heating carbonate ores in limited air.

Step 3: Refining

The most common method is Electrolytic Refining. For example, in copper refining:

Anode: Impure Copper
Cathode: Thin strip of Pure Copper
Electrolyte: Acidified Copper Sulphate solution

[Image of electrolytic refining of copper diagram]

6. Corrosion & Prevention

Corrosion is the gradual destruction of metals by air and moisture. Silver turns black (Ag₂S), Copper turns green (Basic Copper Carbonate), and Iron turns red (Rust).

Prevention Methods:

Galvanization: Coating iron with a thin layer of Zinc.
Alloying: Mixing metals. Example: Stainless Steel (Fe + Ni + Cr).
Anodizing: Forming a thick oxide layer on Aluminium to prevent further oxidation.

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