1. Bohr Diagrams A Bohr diagram is the basic representation of the atom and the location of its sub-atomic particles.

2. Drawing Bohr Diagrams The Basic Steps requires the use and knowledge of the Periodic Table. 1)Determine the number of p +, n & e -. The number of electron in a neutral element will equal the protons. The number of electron in a neutral element will equal the protons. 19K Potassium 39.0983 Atomic # = # of Protons

3. Drawing Bohr Diagrams The Basic Steps requires the use and knowledge of the Periodic Table. 2)Determine the number of energy levels. 3)a) Determine the number of Valence e- b) Place on the outer energy level. 4) Place the remaining e- on the energy levels from the inside out. Use 2n 2 as a guide to place maximum # of e-

4. 2n 2  the maximum # of e - that will fit in an energy level. n  is the energy level of the element. If it is on the 2 nd period n =2, if on the 5 th period n = 5 If n=5 then 2n 2 = 2(5) 2 = 50 e - The 5 th energy level can have 50 e-

5. Bohr Diagram of Sodium 1. Determine the # of p,n, e -. 2. Determine the number of energy levels 3. Determine the number of Valence e- 4. Using 2n 2 place remaining electrons on the energy levels from inside out. 11P 12N  11p, 12n, 11e-  3 energy levels  Na is in group 1 ∴ 1 e - 2e-8e- 1e-

6. How about Copper 1)Copper is a transitional element ∴ it can change its valence electron number. 2) Cu has 29 p, 35n and 29 e- 3) It has 4 energy levels 4) Cu can have 1 or 2 valence e- Lets use 2 for this model. 5) Using 2n 2 we fill inside out untill all e- are used up. 29p 35n 2e - 8e - 17e - 2e -

7. Bohr Diagrams of the 1 st 20 elements On your white boards Pick from three elements from different periods greater than atomic # 20 and draw their Bohr diagram.

8. Your TURN Come on up and pick up a BOHRing worksheet BOHRing worksheet.