properties of ionic compounds

EXAM QUESTION: explain, in terms of electrons and chemical bonds, what happens when potassium reacts with fluorine to form potassium fluoride.

- potassium is in group 1. It has one outer shell electron.

- Fluorine is in group 7. It has seven outer shell electrons.

- In order for both elements to achieve a full outer shell, potassium donates its one outer shell electron to fluorine.

- this means that the potassium atoms become positively charged potassium ions and the fluorine atoms become negatively charged fluorine ions.

name 2 properties of ionic compounds.

- ionic compounds have very high melting and boiling points. this is because the strong electrostatic forces of attraction require a great deal of heat energy to break.

- they cannot conduct electricity when they are solids. this is because when in a solid, the ions (NOT ELECTRONS) are locked in place by the strong electrostatic forces of attraction.