An ion is the name given to an atom which does not have the same number of protons and electrons. Ions have charges - metals have positive charges and non-metals have negative charges. The charges are a result of ionic bonding.

This section will cover some of the main parts of ionic chemistry including...

- Electrolysis
- Reactivity of metals
- Acids and Alkalis
- Reactions of metals with acids

 

Electrolysis

Electro means 'Electricity' and lysis means 'Splitting' and is the name given to the process by which we split ionic compounds into smaller elements or compounds. Making aluminium (for foil, cars, aircraft, road signs etc.) is done by electrolysis. Electrolysis is basically the reverse of ionic bonding - the electrons are returned to the atoms that they come from.

For electrolysis to work the substance to be electrolysed is dissolved or melted so that the ions can move. Two electrodes are placed into the solution - one is positive (an anode) and the other negative (called a cathode). Electricity is passed between the electrodes. The negative ions will move to the anode (positive electrode) and lose their extra electrons. The positive ions will move towards the cathode (negative anode) and collect extra electrons.

The video below shows the electrolysis of sodium chloride. As sodium chloride is a solid, it is first heated so that it melts and the ions are free to move.