Ions

• The atoms of group 8 all have a full outer shell of electrons
• When an atom has a full outer shell the atom becomes very stable and is very unreactive, like a noble gas
• Group 7 elements


  • Need 1 more electron to fill their outer shells
• Group 7 elements


  • Reactive elements
• Group 7 elements


  • Try to get electrons from other atoms so they can have a full outer shell
• Group 1 elements


  • Have 1 electron in their outer shell
• Group 1 elements


  • Want to get rid of electrons to become stable
• All atoms react because they are trying to get a stable, full outer shell of electrons
• Ions


  Atoms that have lost or gained electrons and are electrically charged
• Atoms lose electrons


  They become positively charged metals
• Atoms gain electrons


  They become negatively charged non-metals
• Valency


  Indicates how many electrons are lost or gained
• Groups 1, 2, 3


  • Can lose electrons
• Groups 5, 6, 7


  • Can gain electrons
• It is easier for Group 1 elements to lose electrons than gain them
• Lon


  A tom with a change
• Number of Protons


  Atomic number
• Number of Electrons


  Electron configuration
• Number of Neutrons


  Mass number
• Lon


  • S2
  • Cl
  • P3-
  • Fe³-
  • Cu2+
  • Ca²+
• S2


  • Number of Protons: 16
  • Number of Electrons: 18
  • Number of Neutrons: 16
• Cl


  • Number of Protons: 17
  • Number of Electrons: 18
  • Number of Neutrons: 18
• P3-


  • Number of Protons: 15
  • Number of Electrons: 18
  • Number of Neutrons: 16
• Fe³-


  • Number of Protons: 26
  • Number of Electrons: 23
  • Number of Neutrons: 30
• Cu2+


  • Number of Protons: 29
  • Number of Electrons: 27
  • Number of Neutrons: 34
• Ca²+


  • Number of Protons: 20
  • Number of Electrons: 18
  • Number of Neutrons: 20