Ionic Bonding

• When a metal atom reacts with a non-metal atom, electrons in the outer shell of the metal atom are transferred.
• Metal atoms lose electrons to form positively charged ions.
• Non-metal atoms gain electrons to become negatively charged ions
• the ions produced by metals in groups 1 and 2 and by non-metals in groups 6 and 7 have the electronic structure of a noble gas (group 0)
• The electron transfer during the formation of an ionic compound can be represented by a dot and cross diagram
• Sodium chloride:

  • The sodium atom gives up its outer electron, becoming an Na+ atom
  • the chlorine atom picks up the electron, becoming a Cl- ion
• Magnesium chloride:

  • the magnesium atom gives up its two outer electrons, becoming an Mg2+ ion
  • the oxygen takes the two electrons, becoming an O2- (oxide) ion
• Magnesium chloride:

  • the magnesium atom gives up the two outer electrons, and becomes an Mg2+ ion
  • the chlorine atoms pick up one electron each, becoming 2 Cl- ions
• Sodium Oxide:

  • two sodium atoms each give up their single outer electron, becoming 2 Na+ ions
  • the oxygen picks up the two electrons, becoming an 02- ion