1. 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 ____________________

2. 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 ____________________

3. 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 ____________________

4. 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 ____________________

5. 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 ____________________

6. 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 ____________________