How do main group elements form acids and bases?

Here’s a explanation:

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1. Metals (s-block elements)

• Form basic oxides.
• React with water to make bases.
  • Example:
    • Na₂O + H₂O → NaOH
    • CaO + H₂O → Ca(OH)₂

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2. Nonmetals (p-block elements)

• Form acidic oxides.
• React with water to make acids.
  • Example:
    • CO₂ + H₂O → H₂CO₃
    • SO₃ + H₂O → H₂SO₄

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3. Some metals (like Al, Zn)

• Form amphoteric oxides → react with acid and base.
  • Example:
    • Al₂O₃ + HCl → AlCl₃ + H₂O
    • Al₂O₃ + NaOH → Na[Al(OH)₄]

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4. Hydrides

• Metal hydrides (NaH, CaH₂): react with water → bases
• Nonmetal hydrides (NH₃, HCl, H₂O): act as acids or bases

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5. Lewis acids and bases

• Lewis acid: accepts electrons (BF₃, AlCl₃)
• Lewis base: donates electrons (NH₃, H₂O)

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Simple rule:

• Metals → bases
• Nonmetals → acids
• Some metals/metalloids → both (amphoteric)

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