Ion Formation

• Ion Formation


  The process of atoms gaining or losing electrons to form stable ions
• Metal atoms tend to lose all of their outer-shell electrons to get a full outer-shell
• When metal atoms lose electrons, they become positively charged ions and they are more stable
• Oxidation


  The loss of electrons
• Ion charge


  The number of electrons lost or gained, e.g. 2+ charge means 2 electrons lost
• Non-metal atoms tend to gain electrons to fill their outer-shell
• When non-metal atoms gain electrons, they become negatively charged ions and they are more stable
• Reduction


  The gain of electrons
• Ionic compound formation


  Metal atoms give electrons to non-metal atoms, forming ions with stable full outer-shells
• Forming an ionic compound (Li and O)

  1. Li atoms need to lose 1 electron

  2. O atoms need to gain 2 electrons

  3. 2 Li atoms for every 1 O atom

  4. Li atoms are oxidised (lose electrons)

  5. O atom is reduced (gains electrons)

  6. Li ions have 1+ charge (lost 1 electron)

  7. O ion has 2- charge (gained 2 electrons)

  
• All ions have full outer-shells
• The positive and negative charges balance in an ionic compound
• Atoms in the same periodic table group gain/lose the same number of electrons, forming ions with the same charge