Ions and ionic bonding

• Ions are formed when metal atoms transfer their outer electrons to the outer shells of non-metal atoms. This electron transfer forms charged particles called ions
• Metal atoms form positive ions because they have lost negatively charged electrons. The positive charge on the ion in the same as the number of electrons that are lost
• Non-metal atoms negative ions because they have gained negatively charged electrons. The negative charge on the ion is the same as the number of electrons that are gained by the atom
• The elements in groups 1 and 2 of the periodic table are metals and they form positive ions
• Each group 1 atom forms a 1+ ion by losing 1 electron and each group 2 atom forms a 2+ atom by losing 2 electrons
• The elements in groups 6 and 7 are non-metals and they form negative ions
• Each group 6 atom gains 2 electrons to form a 2- ion and each group 7 atom gains 1 electron to form a 1- ion
• All the ions formed have the same electronic structure as the nearest noble gas because these are stable electronic arrangements
• The ionic bond is the electrostatic attraction between the positive and negative ions