1. Friday, September 12 Element Quiz 1 Today Extra Credit Prototype due today Element Quiz 2 Thursday Atomic Structure Test Friday 19th

2. Electron Shells (Energy Levels) ElectronsElectrons in atoms are in shells The maximum number of electrons in each shell, going from the middle to the outside, is 2-8-8-18atoms

3. 11 12 Sodium Atomic number = Mass Number = 2 - 8 - 1 p+p+ n 23 11 23 protons & neutrons 12 neutrons In a neutral sodium atom the number of protons (11) = the number of electrons (11) - 11 protons ____________________

4. 4 5 Beryllium Atomic number = Mass Number = 2 - 2 p+p+ n 9 4 9 protons & neutrons 5 neutrons In a neutral beryllium atom the number of protons (4) = the number of electrons (4) - 4 protons ____________________

5. 16 Sulfur Atomic number = Mass Number = 2 - 8 - 6 p+p+ n 32 16 32 protons & neutrons 16 neutrons In a neutral sulfur atom the number of protons (16) = the number of electrons (16) - 16 protons ____________________

6. 7 7 Nitrogen Atomic number = Mass Number = 2 - 5 p+p+ n 14 7 14 protons & neutrons 7 neutrons In a neutral nitrogen atom the number of protons (7) = the number of electrons (7) - 7 protons ____________________

7. 14 Silicon Atomic number = Mass Number = 2 - 8 - 4 p+p+ n 28 14 28 protons & neutrons 14 neutrons In a neutral silicon atom the number of protons (14)= the number of electrons (14) - 14 protons ____________________

8. 19 20 Potassium Atomic number = Mass Number = 2 - 8 - 8- 1 p+p+ n 39 19 39 protons & neutrons 20 neutrons In a neutral potassium atom the number of protons (19) = the number of electrons (19) - 19 protons ____________________