Metals

Metals are elements that are typically hard, shiny, malleable, ductile, and good conductors of heat and electricity.
They are found in the Earth's crust and play a key role in Bihar’s economy (e.g., mining, railways, agriculture tools).

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Physical Properties of Metals

• Lustre: Shiny appearance (e.g., gold, silver)
• Malleability: Can be hammered into sheets
• Ductility: Can be drawn into wires
• Conductivity: Conducts heat and electricity well
• Density: Usually high
• Melting Point: Generally high
• Sonorous: Produces sound when struck

📝 PYQ (BPSC): Which metal is most ductile? → Gold
📝 Expected MCQ: Which property allows metal to be drawn into wire? → Ductility

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Chemical Properties of Metals

• React with oxygen → form metal oxides (basic in nature)
  • Example: 4Na + O₂ → 2Na₂O
• React with water → form metal hydroxide + hydrogen gas
  • Example: 2Na + 2H₂O → 2NaOH + H₂↑
• React with acids → form salt + hydrogen gas
  • Example: Zn + HCl → ZnCl₂ + H₂↑
• Displacement Reaction → More reactive metal displaces a less reactive one

📝 PYQ: What is formed when metal reacts with acid? → Salt and hydrogen gas

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Common Metals and Their Uses

📝 Expected MCQ: Which metal is used in electric wires? → Copper

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Alloys of Metals

• Alloy = mixture of two or more metals (or metal + non-metal)
• Improves strength, corrosion resistance, etc.

📝 PYQ: Which is an alloy of copper and tin? → Bronze

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Metals in Bihar – Economic Relevance

🏭 Industry

• Iron used in rail tracks and tools in Jamui, Gaya, Patna regions
• Steel from Bokaro and Burnpur (near Bihar) supports state industry
• Use of brass and bronze in traditional Madhubani handicrafts

🚜 Agriculture

• Metallic tools (ploughs, sickles) are used in rural agriculture
• Government schemes distribute iron-based equipment to marginal farmers

🔋 Mining & Economy

• Bihar has reserves of bauxite (aluminium ore), pyrite, and manganese
• Metal-based MSMEs operate in Muzaffarpur, Patna, Hajipur

🛕 Culture

• Use of gold and silver in Bihar’s religious festivals and jewelry trade
• Statues made from bronze (e.g., Nalanda Museum artefacts)

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Metal Reactivity Series (Short Glance)

• Order from most to least reactive:
  K > Na > Ca > Mg > Al > Zn > Fe > Pb > Cu > Ag > Au
• Helps predict displacement reactions and corrosion resistance

📝 Expected MCQ: Which is more reactive: Iron or Copper? → Iron

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Environmental Note

• Corrosion: Metals like iron rust in presence of water and air
  • Rust formula: Fe₂O₃·xH₂O
• Galvanization: Coating iron with zinc to prevent rust
• Bihar's railway stockyards apply galvanization to parts for long life

📝 PYQ: What is rusting of iron? → Formation of iron oxide due to air and water

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PYQs + Expected MCQs

📝 PYQ (BPSC): Most ductile metal? → Gold
📝 PYQ (BPSC): Rust is formed by which metal? → Iron
📝 Expected MCQ: Which metal is used in railway tracks? → Iron
📝 Expected MCQ: Brass is an alloy of? → Copper and Zinc
📝 Expected MCQ: Which property makes metal sonorous? → Sound-producing ability

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Quick Revision Points

• Metals = lustrous, ductile, malleable, good conductors
• React with acid → Salt + H₂
• Iron, Copper, Aluminium – widely used
• Bihar uses metals in rail, farming, crafts
• Alloys = brass, bronze, steel
• Rust = iron oxide, prevented by galvanization
• Most reactive → K, Least → Gold

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Sources Used

• NCERT Science Class 8–10
• Lucent GK – Chemistry Section
• Drishti Science Quick Book
• EduTeria + Ghatna Chakra PYQs (BPSC, DPRO, CDPO)
• Bihar Industrial Investment Promotion Policy
• Bihar Agriculture Department – Tool Schemes
• Railway Workshop Reports – Danapur Division
• Nalanda & Bihar Museum Catalogs