Formation of Ions.

• Ion

  A charged particle, could be a single atom or a group of atoms
• Formation of ions

  1. Atoms gain or lose electrons

  2. To have a full outer shell

  3. For stability
• Group number

  Tells us how many electrons the atoms of that group have in the outermost shell
• Atoms need to lose or gain electrons

  To become stable
• Losing and gaining electrons

  Requires energy
• Group 1 elements (alkaline metals)

  • Only have to lose 1 electron to have a full outer shell
  • Easily lose that electron to become 1+ ions
• Group 2 elements

  • Can easily lose 2 electrons to become 2+ ions
• Group 6 elements

  • Gain 2 electrons to become 2- ions
• Group 7 elements

  • Have to gain 1 electron
• Groups 3-5 elements


  • Would have to lose or gain 3-4 electrons, which requires a lot of energy, so they don't form ions often