1. Electron Configuration Methods for expressing electron locations: 1.Configuration 2.Orbital Notation

2. ELECTRON CONFIGURATION Electrons find homes in orbitals Electrons fill orbitals from lowest energy level FIRST, to highest energy level, LAST. REMEMBER! – s holds 2 – color the s blockORANGE – p holds 6 – color the p blockPURPLE – d holds 10 – color the d block GREEN – f holds 14 – color the f block BLUE

3. GRAB COLORS!

4. LET’S PRACTICE Let’s write the electron configuration for Mg. What is the atomic number of Mg? _____ How many electrons does Mg have? ______ Write the electron configuration for Mg. 12 1s 2 2s 2 2p 6 3s 2

5. RULES 1.e- occupy orbitals of lowest energy first 2. orbitals hold up to two electrons of opposite spin (clockwise – counterclockwise) 3. one e- enters each orbital until all orbitals have 1 e- with the same spin direction, THEN it’s paired with e- with different spin (LONERS FIRST  PARTNERS SECOND)

6. ORBITAL NOTATION We can also use diagrams with arrows to show electrons and their spin in a diagram called orbital notation. Each block represents an orbital (like an electron parking spot). 1 atom of Li # of P + = 3 # of e- = 3   

7. 1 atom of F # of P + = 9 # of e- = 9       LONERS FIRST PARTNERS SECOND OPPOSITE SPIN OCCUPY LOWEST ENERGY FIRST BEFORE MOVING TO HIGHER ENERGY LEVEL

8. ORBITAL NOTATION YOU TRY SULFUR!