1. ELECTRONIC CONFIGURATION

2. ELECTRONIC CONFIGURATION -arrangement of electrons in the space around the nucleus of an atom. -distribution of electrons in the orbitals of an atom.

3. ELECTRONIC CONFIGURATION ENERGY LEVEL (electron shell) -orbit where electrons spin around the nucleus of an atom.

4. ELECTRONIC CONFIGURATION

5. ELECTRONIC CONFIGURATION ENERGY SUBLEVEL (subshell) -energy subdivision of a principal energy level. -designated by: s(sharp) p (principal) d (diffuse) f (fundamental)

6. Mnemonic Device for Electronic Configuration

7. Electronic configuration of: IodineI53 = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5

8. Electronic configuration of: Silicon Si14 = 1s2 2s2 2p6 3s2 3p2 LeadPb82 = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p2

9. RULES AND CONCEPTS

10. AUFBAU’S PRINCIPLE -”aufbau” –building up -principle of electrons filling up the orbitals in order of increasing energy.

11. PAULI’S EXCLUSION PRINCIPLE -an orbital may be occupied by a maximum of two (2) electrons. -the maximum number of electrons in each of the sublevels and orbitals:

13. HUND’S RULE -if electrons have more than one equivalent orbital available, they will half-fill each of the equivalent orbitals before filling the second half of each.

14. Example: Electronic configuration of: 14N = 1s2 2s2 2p37

15. Electronic configuration of:56Fe= 1s22s2 2p6 3s2 3p6 4s2 3d 626