1. How Atoms Form Ions

2. How Atoms form Ions An ion is an atom that has a charge The amount of protons and neutrons in an atom are always the same. Atoms have the ability to lose or gain electrons. If an atom gains an e- it will have a charge of -1. If an atom loses an e- it will have a charge of +1.

3. Why Do Atoms form Ions? All atoms want to be stable. To become stable they want t have a full outer/valence shell. To decide if an atom will gain or lose electrons, think of the easiest way for it to get a full outer shell. We can draw a Bohr diagram of the ion formed for various atoms.

4. e.g. Lithium Lithium Atom Lithium Ion 3p+ 4n 3p+ 4n 1+ Li 1+ We write the symbol for the Ion Li+

5. e.g. Oxygen Oxygen Atom Oxygen Ion 8p+ 8n 8p+ 8n 2- O O We write the symbol for the Ion O 2-

6. Ion Formation Worksheet page 15 Let me know if you need help.