Ionic Bonding

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• Electrostatic force of attraction between oppositely charged(cations and anions) ions in a network

• Consists of a metal and a non-metal combined together

• Examples

  • $NaCl$
    • Sodium loses an electron and becomes a cation, with the stability of a noble gas
      • $Na=2,8,1\to N{a}^{+}=2,8+\overline{e}$
    • Chloride gains an electron, and becomes an anion, with the stability of a noble gas
      • $Cl=2,8,7\to C{l}^{+}=2,8,8+\overline{e}$
  • $MgC{l}_2$
    • Magnesium loses 2 electrons and becomes a cation, with the stability of a noble gas
      • $Mg=2,8,2\to M{g}^{2+}=2,8+2\overline{e}$
    • Chloride gains an electron, and becomes an anion, with the stability of a noble gas
      • $Cl=2,8,7\to C{l}^{+}=2,8,8+\overline{e}$
      • $Cl=2,8,7\to C{l}^{+}=2,8,8+\overline{e}$
    • Therefore, 2 chlorine ions bond with 1 magnesium ion
  • $MgO$
  • $CaC{O}_3$

• Ions exist in a 3D, ionic lattice

• Cannot conduct electricity as a solid

  • Ions are in a fixed lattice
  • Therefore, the ions/electrons are fixed and cannot move
  • Charge cannot be conducted

• Conducts electricity when liquid/molten/dissolved

  • The ions do not exist in a lattice
  • Therefore, they are free/mobile
  • Charge can be conducted

• High melting and boiling points

  • Ions are in a fixed lattice
  • Ionic bonds are strong
  • Therefore, the energy required to break up the lattice is large

• Brittle

  • Ions exist in a lattice
  • When a force is applied, layers of the lattice are displaced
  • Therefore, ions with like charges come close to each other, and repel each other
  • The lattice shatters, and is therefore brittle

• Often soluble in water

  • Depends on ESF of the lattice
  • If the intermolecular forces of the $H_{2}O$ molecule is greater than the lattice, the lattice is displaced and it dissolves
  • If the lattice’s ESF is greater than the intermolecular forces of the $H_{2}O$ molecule, it is not displaced and is therefore not soluble

• Lewis Diagrams are known as dot-dot or dot-cross

  Sodium Chloride, $NaCl$

  Magnesium Chloride, $MgC{l}_2$

Metallic Bonding

Covalent Bonding