The document discusses the electronic configuration of atoms, which is the arrangement of electrons in an atom's orbitals. It defines the key terms of energy levels and sublevels, which are the orbitals where electrons are arranged. Examples of electronic configurations are given for several elements, such as iodine and silicon. Rules for determining electronic configuration, such as Aufbau's principle, Pauli's exclusion principle, and Hund's rule are also outlined.

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 CONFIGURATIONENERGY LEVEL (electron shell)-orbit where electrons spin around the nucleus of an atom.

4. ELECTRONIC CONFIGURATION

5. ELECTRONIC CONFIGURATIONENERGY 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 3p2LeadPb82= 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