Electron transfer between atoms, forming ions with opposite charges
Ionic bonding atoms lose or gain electrons
If the shell has one or two electrons they are keen to get rid of it and if a atom has 6 or 7 they are keen to gain to create a full outer shell
Group1&2 and 6&7 are the most likely to from ions
ionic compound are made up of positive charge part and a negative charge part
Sodium chloride contains Na+ (+1) and Cl-(-1) ions
(+1)+(-1)=0 the charge are balanced with on of each ions so the formula of sodium chloride = NaCl
Magnesium chloride contains Mg2+ (+2) and Cl- (-1) ions becouse of a chloride ions only has a 1- charge we will need two of them to balance out the 2+ charge of magnesium ions this gives us the formula = MgCl2