1. 11.4 A,B

2. Definitions Orbital – a three dimensional region in which there is a high probability of finding an electron in an atom (represented by orbital box diagrams) Electron configurations- shows the electron arrangement of certain elements

3. Principles Aufbau’s Principle- electrons fill orbitals starting at the lowest available energy levels. ( there is a definite order in how the energy levels are filled) Pauli’s exclusion Principle- an atomic orbital can hold a maximum of two electrons, and those two electrons must have opposite spins. Hund’s rule-states that unoccupied orbitals will be filled before occupied orbitals are reused (by electrons having different spins).

4. Order of orbital diagrams and electron configurations

5. Orbital Filling

6. s, p, d and f orbitals An orbital is represented in the diagrams by a box that can hold 2 electrons s orbital can hold up to 2 electrons (1 box) p orbitals can hold up to 6 electrons (3 boxes) d orbitals can hold up to 10 electrons (5 boxes) f orbitals can hold up to 14 electrons (7 boxes)

7. Orbital Diagrams

8. Orbital Diagrams to Electron Configurations

9. Noble Gas Electron Configuration Shortcut

10. Noble Gas Configuration

11. Lewis Dot Structures shows valence electrons