2. Levels/Shells Principal Quantum Number (1-7) (2 x level 2 ) determines the amount of electrons that can fit into that energy level Electron Organization

3. Sublevels/Subshells The specific cloud shape within the level. s p d f

4. 1 s shape

5. 3 p shapes

6. 5 d shapes

7. 7 f shapes

8. Orbitals The specific area within the cloud shape. Each orbital holds 2 e - max. s = 1 orbital, holds up to 2 e - p = 3 orbitals, holds up to 6 e - d = 5 orbitals, holds up to 10 e - f = 7 orbitals, holds up to 14 e -

10. Rules for e - filling in the atom 1.Aufbau Principle – an atom fills with e - in a specific order to achieve lowest energy. 2. Pauli’s Principle – no 2 e - in an orbital can have the same spin. (why only 2 e- max) 3. Hund’s Rule – In a sublevel, each orbital gets an electron before the electrons pair up. Creates lower energy.

11. Orbital Notation(diagrams) Shows orbitals (circles,lines,boxes) and position of electrons (arrows) Ex: Carbon 6 e - 1s 2s 2p

12. Electron Configuration Gives the level, sublevel, and number of electrons within an atom Ex: Carbon 6 e - 1s 2 2s 2 2p 2

13. Sn 50 e - 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 2 Noble gas notation (shorthand) puts brackets around the noble gas that completed the row above the element [Kr] 5s 2 4d 10 5p 2

14. Valence Level Level holding the outer most e - in atom 8 valence e- max Determines the element’s properties

15. Electron Dot Diagrams -Element symbol with dots (valence e-) - 8 dots max, grouped by orbitals EX: Lithium 3 e - Bromine 35 e - 1s 2 2s 1 [Ar]4s 2 3d 10 4p 5 Li Br