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 how many electrons the atoms of that group have in the outermost shell
• Atoms need to lose or gain electrons until their outermost shell is full


  To become stable
• Losing and gaining electrons


  Requires energy
• Group 1 elements (alkaline metals)

  • Only have to lose 1 electron to a 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 to become 1- ions
• 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. If the atom is becoming a positive ion and losing electrons, then place the electron on the right of the reaction

  2. If the atom is becoming a negative ion and gaining electrons, then place the electron on the left of the reaction to show the combination of atoms
• Transfer of electrons:

  • From an atom that has too many electrons to an atom that dosen't have enough electrons. Once this electron has been transferred, both atoms become ions with full outer shell of electrons. The two ions would have opposite charges so they would be attracted to each other by electrostatic forces to form an ionic compound.