gcse

• An ion is a charged particle formed when atoms either lose or gain one or more electrons.
• Ions are shown by the symbol of the element that forms them and a ‘+’ or ‘-‘ symbol indicating the amount of charge on the ion. e.g. Na⁺, Mg²⁺, Cl^-, O^2-.
• Metals form positive ions. and non-metals usually form negative ions.  
• Ions can only move when in a solution or when in a liquid, not when in a solid. 
• Electrolysis is the process in which electricity is applied to a solution or liquid contains ions. It is often used to separate compounds into the elements that make them.
• Positive ions are attracted to the negative electrode. Negative ions are attracted to the positive electrode.