ionic bonding

• what is an ion?


  An ion is an atom or molecule that has gained or lost electrons, resulting in a positive or negative charge.
• why does this loss or gain of electrons take place?


  to gain a full outer shell of electrons
• what happens when metal atoms lose electrons?


  it becomes positively charged
• non metals gain electrons to become negatively charged
• The electron transfer during the formation of an ionic compound can be represented by a dot and cross diagram, eg for sodium chloride