Introduction to Carbon

📚 Key Concepts

🔹 Real-Life Example

Look around you – your wooden desk (cellulose), the plastic pen you’re holding (polymers), the cotton shirt you’re wearing (cellulose), and even the breath you exhale (CO₂) – all contain carbon! What makes carbon so special that it can form such diverse compounds? It’s like carbon is the ultimate building block of nature!

Carbon: A non-metallic element with atomic number 6, capable of forming four covalent bonds and existing in various allotropic forms. It’s the basis of all organic compounds.

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🧪 Important Concepts

🔸 Unique Properties of Carbon

  • Tetravalency: Carbon has 4 valence electrons, can form 4 bonds
  • Catenation: Ability to bond with other carbon atoms forming chains
  • Small atomic size: Forms strong covalent bonds
  • Forms multiple bonds: Single, double, and triple bonds possible
  • Versatile bonding: Can bond with H, O, N, S, halogens, and other elements

🔸 Why Carbon Forms Covalent Bonds

Carbon needs 4 more electrons to complete its octet. Instead of losing or gaining electrons (which would require too much energy), it shares electrons through covalent bonding. This sharing creates stable compounds.

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🔸 Allotropes of Carbon

Diamond:

  • Each carbon bonded to 4 other carbons in 3D network
  • Hardest natural substance
  • Does not conduct electricity
  • Used in jewelry, cutting tools, drilling

Graphite:

  • Each carbon bonded to 3 other carbons in layers
  • Soft and slippery (layers slide over each other)
  • Conducts electricity (free electrons)
  • Used in pencils, lubricants, electrodes

Fullerenes (C₆₀):

  • Football-shaped molecules
  • Recently discovered allotrope
  • Used in nanotechnology

🔍 Advanced: Catenation Power

Carbon’s ability to form long chains is unmatched. While silicon can also show catenation, C-C bonds (355 kJ/mol) are much stronger than Si-Si bonds (222 kJ/mol), making carbon compounds more stable.