Electron configurations provide information about the location of electrons in an atom's orbitals. There are three main rules for determining electron configurations: 1) electrons fill orbitals starting with the lowest energy levels and moving upwards, 2) the Pauli exclusion principle states that no two electrons can occupy the same orbital with the same spin, and 3) Hund's rule states that electrons will occupy orbitals singly before pairing up. Writing out electron configurations involves determining the element's number of electrons and following the Aufbau principle of filling orbitals in order of increasing energy.

1. Electron Configuration

6. ORBITAL DIAGRAM

7. Practice Which is the correct electron configuration for the element titanium (Ti, atomic number 22)? What element has the electron configuration notation 1s 2 2s 2 2p 6 3s 1 ? Which is the correct orbital notation for the element aluminum (Al, atomic #13)? The following orbital diagram is for the element ______________.

8. Electron Configurations and the Periodic Table

9. We can use the periodic table to predict the level and sublevel of an element.

10. BLOCKS

12. NOBLE GAS CONFIGURATION The electron configuration for gold (Au) is: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 9 Gold (Au) is in the 6 th row of the periodic table : This gives us: [Xe] 6s 2 4f 14 5d 9

13. Noble gas notation

14. MORE EXAMPLES Noble Gas Notation: C = [He]2s 2 2p 2 Te = [Kr]5s 2 4d 10 5p 4 I = [Kr]5s 2 4d 10 5p 5