Ions

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  Calculating sub atomic particles in ions: For example, the magnesium ion can be represented as  

  • The magnesium ion has an atomic number of 12, therefore it has 12 protons and 12 electrons
  • But, it has a 2+ charge which means that it has lost two electrons
  • The mass number of the magnesium ion is 24, so it has 24 - 12 = 12 neutrons
  • The PEN numbers for the magnesium ion are thus:
  • protons= 12
  • electrons = (12 - 2 =) 10
  • neutrons = (24 - 12 =) 12