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 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
  • Requires a lot of energy
  • Generally don't form ions
• Equation for ion formation

  1. Atom goes to form ion + electron (for positive ions)

  2. Atom + electron goes to form ion (for negative ions)
• Atoms losing/gaining multiple electrons

  Atom goes to form ion + multiple electrons
• Magnesium forms a 2+ ion and 2 electrons
• Oxygen forms a 2- ion by gaining 2 electrons
• Ionic compounds are formed when metals react with non-metals