ionic bonding

• ionic (metals + non-metals)

  • transfer of electrons between atoms
  • produce anions and cations
• anion = non -metal atoms gain electrons to become negatively charged ions
• cation= metal atoms loose electrons to become positively charged ions
• an ion is an atom or a group of atoms with a positive of negative charge
• electrons, protons and neutrons in an ion given the mass and atomic number

  in an ion there if a different nr of electrons to protons therefore :

  • work out how many electrons of an atom of the element would have e.g. oxygen would have 8
  • work out if its a loss or gain of electrons
  • calculate the nr of electrons in the atom + electrons gained or - electrons lost
• group 0 have 8 electrons in their outer shell

  group 1 metals will loose an electron and form +1 ions

  group 2 metals will loose two electrons and form 2+ ions

  group 6 metals will gain two electrons and form 2- ions

  group 7 metals will gain one electron and form 1- ions
• the meaning of endings

  -ide, the compound contains two elements (one is a non-metal -ve ion)

  -ate, the compound contains at least 3 compounds, one of which is oxygen
• ionic compounds


  • oxide $O^{2-}$ ion (sodium oxide)
  • hydroxide $OH^-$ ion (sodium hydroxide)
  • halide -1 halide ion (sodium chloride)
  • nitrate $NO_3^-$ ion (sodium nitrate)
  • carbonate $CO_3^{2-}$ ion (sodium carbonate)
  • sulphate $SO_4^{2-}$ ion (sodium sulphate)
• structure of an ionic compound


  • lattice structure
  • regular arrangement of ions
  • held together by strong electrostatic forces (ionic bonds) between oppositely-charged ions