1. Workshop: Electron Configurations
Forensic Chemistry
By PresenterMedia.com

2. Noble Gas Configurations
Also known as Shorthand Notation
Step 1
Find the closest noble gas to the atom (or ion) with LESS electrons
Step 2
Write the symbol for the noble gas in brackets [ ]
Step 3
Find the electron configuration that the noble gas and the atom (or ion) have in common
Step 4
After the brackets, write the part of the atom (or ion)’s e-config. that is NOT in the noble gas
Step 5
Count the number of electrons to check if they match the total number needed

3. Practice Noble Gas Configuration
……. Or Shorthand Notation
Practice Noble Gas Configuration Cl K Ca I Bi
Electron Configuration
Noble Gas Configuration
- 1s22s22p63s23p5 - 1s22s22p63s23p64s1 - 1s22s22p63s23p64s2 - 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 1s22s22p63s23p63d104s24p64d105s25p64f145d106s26p3
[Ne] 3s23p5
[Ar] 4s1
[Ar] 4s2
[Kr] 4d105s25p5
[Xe] 4f14 5d10 6s2 6p3

4. Exceptions to the Aufbau Principle
Says electrons fill lowest energy levels first
Atoms are MORE stable when they have their d-shell “half-filled”
Cr has [Ar]4s13d5
Mo?
Atoms are MORE stable when they have their d-shell “filled”
Cu has [Ar]4s13d10
Ag ?
Au ?