A small piece of sodium metal is placed in a flask of chlorine gas. A little water helps expose the sodium so it can react with the chlorine gas. The reaction releases a lot of heat as the ionic ...

Dot and cross diagrams help us to model when ions are formed from atoms. Here’s an example using sodium and chlorine. They form ions which bond to form sodium chloride. 2. Work out how many ...

Tell students that when an atom gains or loses an electron, it becomes an ion. Sodium loses an electron, leaving it with 11 protons, but only 10 electrons. Since it has 1 more proton than electrons, ...