1. Starter Give the electronic configuration of an atom of: - 9 4 Be - 24 12 Mg - 40 20 Ca Where are these elements found in the periodic table?

2. Forming Ions

4. Atoms are most stable when they have a f……… o…………… energy level of e……………………. Most atoms have to l………… or g………… electrons to do this. Example on the board

5. Atoms which have lost or gained e…………………… are called i……….

6. Sodium = 23 11 Na 1.Draw an atom of sodium, showing all of the electrons. 2.Will sodium lose or gain electron(s)? Draw the electronic configuration of the sodium ion. 3.Work out the charge on the ion.

7. Draw an atom of each of the following, showing the electronic configuration. For each, work out how many electrons it loses. Draw the electronic configuration of the ion. Work out the charge on the ion. 7 3 Li 9 4 Be 24 12 Mg 27 13 Al

8. Chlorine = 35.5 17 Cl 1.Draw an atom of chlorine, showing all of the electrons. 2.Will chlorine lose or gain electron(s)? Draw the electronic configuration of the chlorine ion. 3.Work out the charge on the ion.

9. Draw an atom of each of the following, showing the electronic configuration. For each, work out how many electrons it loses. Draw the electronic configuration of the ion. Work out the charge on the ion. 19 9 F 16 8 O 32 16 S 14 7 N

10. 1.Explain why the group 0 elements do not lose or gain electrons. 2.From the work you’ve done today, can you figure out the formula of sodium chloride, magnesium chloride and aluminium chloride?