Properties and Reactions — Revision Notes

⚡ 30-Second Revision

Metals: — Electropositive, lose electrons, form cations. Shiny, malleable, ductile, good conductors (heat/electricity). High MP/BP, high density. Basic/amphoteric oxides. Reducing agents.
Non-metals: — Electronegative, gain/share electrons, form anions/covalent bonds. Dull, brittle (solids), poor conductors (except graphite). Low MP/BP, low density. Acidic/neutral oxides. Oxidizing agents.
Reactivity Series: — K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au > Pt. (Decreasing reactivity).
Metal + O₂: — Metal oxide (basic/amphoteric).
Non-metal + O₂: — Non-metal oxide (acidic/neutral).
Metal + H₂O: — Metal hydroxide/oxide + H₂ (reactivity dependent).
Metal + Dilute Acid: — Metal salt + H₂ (if metal > H in series).
Displacement Reaction: — More reactive metal displaces less reactive metal from salt solution.

2-Minute Revision

Metals and non-metals are fundamentally distinguished by their electron behavior. Metals are electropositive, readily losing electrons to form cations, which explains their characteristic physical properties: metallic luster, malleability, ductility, and excellent electrical and thermal conductivity, all stemming from the 'sea' of delocalized electrons.

Chemically, they are reducing agents, forming basic or amphoteric oxides. Their reactivity is governed by the reactivity series, dictating reactions with water, acids, and other metal salts in displacement reactions.

Non-metals are electronegative, tending to gain or share electrons. This results in their physical properties: dull appearance, brittleness (if solid), and poor conductivity (except graphite). Chemically, they act as oxidizing agents, forming acidic or neutral oxides.

Understanding these core differences, especially the electron-losing vs. electron-gaining tendencies, is key to predicting reaction outcomes and comprehending their diverse applications, from industrial metallurgy to environmental chemistry.

Remember the exceptions and the reactivity series for quick recall in Prelims.

5-Minute Revision

A comprehensive understanding of metals and non-metals begins with their atomic structure. Metals, with few valence electrons, readily lose them, becoming electropositive and forming cations. This electron delocalization creates metallic bonds, responsible for their high electrical and thermal conductivity, malleability, ductility, and characteristic luster.

They are typically dense solids with high melting points. Chemically, metals are potent reducing agents, forming basic oxides (e.g., Na₂O) or amphoteric oxides (e.g., Al₂O₃) that react with water to form bases.

Their reactivity varies significantly, systematically ordered in the reactivity series (K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au > Pt), which is crucial for predicting reactions with water, dilute acids (producing H₂ gas if more reactive than H), and displacement reactions where a more reactive metal displaces a less reactive one from its salt solution.

Non-metals, conversely, have more valence electrons and tend to gain or share electrons, making them electronegative. Physically, they are generally dull, brittle (if solid), and poor conductors of heat and electricity (insulators), with graphite being a notable exception due to its unique bonding.

They exist in all three states of matter at room temperature and typically have lower melting points. Chemically, non-metals are oxidizing agents, forming acidic oxides (e.g., CO₂, SO₂) or neutral oxides (e.

g., CO, NO) that react with water to form acids. They react with metals to form ionic compounds and with other non-metals to form covalent compounds. Key applications include their role in industrial processes (e.

g., extraction of metals, production of fertilizers), environmental issues (e.g., acid rain from non-metal oxides), and material science (e.g., alloys, semiconductors). For UPSC, focus on the 'why' behind these properties, the exceptions, and the practical implications of their reactions.

Prelims Revision Notes

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Physical Properties:

* Metals: Luster (shiny), Malleable (sheets), Ductile (wires), Good conductors (electrical & thermal), High MP/BP, High density, Solids (except Hg). * Non-metals: Dull (except Iodine, Diamond), Brittle (solids), Poor conductors (except Graphite), Low MP/BP, Low density, All states.

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Chemical Properties:

* Electron Tendency: Metals lose e⁻ (electropositive, cations); Non-metals gain/share e⁻ (electronegative, anions/covalent). * Oxides: Metals form Basic (Na₂O, MgO) or Amphoteric (Al₂O₃, ZnO); Non-metals form Acidic (CO₂, SO₂) or Neutral (CO, N₂O). * Redox Role: Metals are Reducing Agents; Non-metals are Oxidizing Agents.

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Reactivity Series (Memorize): — K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au > Pt.

* Reactions with Oxygen: Metals form oxides (speed varies). Non-metals form acidic/neutral oxides. * Reactions with Water: Highly reactive metals (K, Na) react with cold H₂O; Mg with hot H₂O; Zn, Fe with steam.

Products: Metal hydroxide/oxide + H₂. * Reactions with Acids (Dilute): Metals > H in series react to form Salt + H₂. Metals < H do not react. * Displacement Reactions: More reactive metal displaces less reactive metal from its salt solution (e.

g., Fe + CuSO₄ → FeSO₄ + Cu).

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Exceptions: — Graphite (non-metal, conducts), Iodine (non-metal, lustrous), Mercury (metal, liquid), Diamond (non-metal, high MP/BP, insulator). Amphoteric oxides (Al₂O₃, ZnO) react with both acids and bases.
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Key Terms: — Malleability, Ductility, Luster, Conductivity, Reactivity Series, Electropositivity, Electronegativity, Basic Oxide, Acidic Oxide, Amphoteric Oxide, Reducing Agent, Oxidizing Agent.

Mains Revision Notes

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Conceptual Foundation: — Link all properties and reactions to atomic structure (valence electrons, ionization energy, electronegativity). This provides the 'why' for all observations.
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Comparative Analysis: — Be prepared to compare and contrast metals and non-metals across all physical and chemical properties. Use a structured approach (e.g., table format in mind) and provide examples for each point. Emphasize the underlying bonding differences (metallic vs. covalent/ionic).
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Reactivity Series - Significance & Applications:

* Predictive Power: Explain how it predicts displacement reactions (metal-salt, metal-acid, metal-water). Provide balanced chemical equations. * Industrial Relevance: Detail its role in extraction of metals (e.g., electrolysis for reactive metals, carbon reduction for moderately reactive), corrosion prevention (sacrificial protection), and electrochemical cells.

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Environmental & Industrial Implications:

* Metal Reactions: Corrosion (economic loss, resource depletion), heavy metal pollution. * Non-metal Reactions: Acid rain (SOₓ, NOₓ), global warming (CO₂), industrial emissions. * Mitigation: Green chemistry, pollution control technologies, sustainable materials, recycling.

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Interdisciplinary Connections: — Articulate how this topic connects to periodic table trends, chemical bonding, acids, bases and salts, and carbon and its compounds. This demonstrates a holistic understanding.
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Emerging Technologies: — Briefly touch upon how fundamental properties are leveraged in advanced materials (e.g., alloys, semiconductors, nanomaterials) and green energy solutions.

Vyyuha Quick Recall

Reactivity Series Mnemonic (Vyyuha Memory Palace):

Imagine a grand palace where elements reside. The most powerful (reactive) elements live on the top floor, and the least powerful live in the basement.

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Potassium (K) - The King, lives in the penthouse, very reactive.
Sodium (Na) - The Prince, just below the King, also very reactive.
Calcium (Ca) - The Count, reactive.
Magnesium (Mg) - The Marquis, reactive.
Aluminium (Al) - The Archduke, moderately reactive.
Carbon (C) - The Commoner (non-metal, included for reduction reference), moderately reactive.
Zinc (Zn) - The Zealot, moderately reactive.
Iron (Fe) - The Iron Knight, moderately reactive.
Tin (Sn) - The Tinker, moderately reactive.
Lead (Pb) - The Lord, moderately reactive.
Hydrogen (H) - The Herald (non-metal, reference point), below which metals don't displace H from acids.
Copper (Cu) - The Common Guard, less reactive.
Silver (Ag) - The Silver Spoon, less reactive.
Gold (Au) - The Golden Crown, least reactive, found in the treasury (free state).

Properties Mnemonic (Vyyuha's 'METAL' vs 'NON-METAL' Checklist):

M - Malleable & Ductile (Metals YES, Non-metals NO) E - Electrical Conductivity (Metals HIGH, Non-metals LOW, except Graphite) T - Thermal Conductivity (Metals HIGH, Non-metals LOW) A - Appearance (Metals LUSTROUS, Non-metals DULL, except Iodine) L - Lose Electrons (Metals YES, Non-metals NO)

N - Nature of Oxides (Metals BASIC/AMPHOTERIC, Non-metals ACIDIC/NEUTRAL) O - Oxidizing Agent (Metals NO, Non-metals YES) N - Non-malleable/Ductile (Non-metals YES, Metals NO) M - Melting/Boiling Points (Metals HIGH, Non-metals LOW) E - Electronegative (Non-metals YES, Metals NO) T - Tendency to Gain/Share Electrons (Non-metals YES, Metals NO) A - All States (Non-metals YES, Metals Solids only except Hg) L - Low Density (Non-metals YES, Metals NO)