Types of Bonding

How Atoms Bond

• Atoms react to achieve full valence shells.
• Bonding involves valence electrons, which can be lost, gained, or shared.

Types of Bonding

• Ionic Bonding: Between metal and non-metal atoms.
• Covalent Bonding: Between non-metal atoms.
• Metallic Bonding: Between metal atoms.

Ionic Bonding Details

• Occurs between ions (electrically charged particles).
• Electrons are transferred from the metal to the non-metal.
• Creates electrostatic attraction between negative anions and positive cations.
• Ionic compounds are overall neutral and form regular crystal structures.
• Criss-Cross Rule for Formulas:
  • Write symbols with charges as superscript.
  • Cross over valencies (charges) as subscripts (omit +/-).
  • Subscript 1 is never written.
  • Use brackets for two or more polyatomic ions (e.g., OH^-).
  • Simplify if possible.
• Polyatomic Ions: Examples include Carbonate (CO3^{2-}) and Sulphate (SO4^{2-}).

Properties of Ionic Compounds

• High Melting and Boiling Points: Due to very strong bonds requiring significant energy to separate.
• Hard: Uniform, repeating lattice structure with strong attractions.
• Brittle: Disruption to the lattice causes like-charges to align and repel.
• Solubility: Most dissolve in water.
• Electrical Conductivity:
  • Do NOT conduct when solid: Ions are fixed in a lattice and cannot move.
  • DO conduct when dissolved or molten: Ions are free to move and carry charge.