1. Electron Configuration

2. Electron configurations show the arrangement of electrons within atoms.
Remember:
Atom = nucleus + electron cloud

3. The Electron Cloud

4. There are specific energy levels within the cloud where there is a high probability of finding electrons
Lower energy levels
are closer to the nucleus.

5. 1. Principle Energy Levels (PEL)7 6 5 4 3 2 1
Highest Energy
Lowest Energy
My movie theater would have 7 floors

6. s p d f 2. Orbital Sublevels
The first floor would have one row, the “s” row!

7. s:
Spherical shape
the size of the s-orbital increases as PEL increases 1s 2s 3s

8. p:
Dumbell shaped
Arranged in 3 planes x z y pz z x y py y x px z

9. d:
Four double dumbells and one dumbell with a donut

10. f:
Too complicated to draw!

11. 3. Orbitals s = 1 ___ p = 3 ___ ___ ___ d = 5 ___ ___ ___ ___ ___
I would put benches
in each row!
s = 1 ___
p = 3 ___ ___ ___
d = 5 ___ ___ ___ ___ ___
f = 7 ___ ___ ___ ___ ___ ___ ___

12. Two people could sit on each bench!
4. Electrons
Two people could sit on each bench!

13. 5 Ways to Write Electron Configurations
Complete
Abbreviated
Orbital Notation
Electron Dot Diagram
Quantum Numbers

14. Let’s stop and practice some different ways to write electron configurations!

15. Complete Configuration
· Remember, electrons are located in orbitals, regions around the nucleus that correspond to specific energy levels. · A complete configuration shows the PEL, sublevel, and orbital for each electron in an atom.

16. 1 H 2 He 3 LI 4 Be 5 B

17. · d’s are “cheaters”, they dive back in one level
· Why? Because energy-wise, it is easier to fill the 4s level with two electrons than the 3d with10 electrons
· Just follow the Aufbau diagram!
=1s22s22p63s23p64s23d6 26 Fe

18. · f’s are “really big cheaters”, they dive back in two levels
· Just follow the Aufbau diagram.
· Double check the number of electrons when you are finished (OK to use calculator).
=1s22s22p63s23p64s23d10 4p65s24d105p66s24f145d106p2 82 Pb

19. Abbreviated Configuration3 LI
[He] 2s1 26 Fe
[Ar] 3d6 4s2 11 Na
[Ne] 3s1 17 Cl
[Ne] 3s2 3p5 82 Pb
[Xe] 4f14 5d10 6s2 6p2

20. Orbital Notation 1 H 2 He 3 LI 5 B 6 C

21. 7 N 8 O 22
TiI 33 As
Do on your own

22. Electron Dot Diagram 1 H 2 He 3 LI 4 Be 5 B

23. 7 N 8 O 9 F 10 Ne

24. Electrons and Light

25. Electrons Act Like Both Particles and Waves
When electrons move about the nucleus within their orbitals, they are behaving as particles with mass.
However, electrons also behave as waves of energy.

26. Light is an Electromagnetic Wave

27. The frequency and wavelength of light are INVERSELY related
The frequency and wavelength of light are INVERSELY related. As frequency increases, wavelength decreases.

28. The Electromagnetic Spectrum
ROY G BIV

29. Light Provides Information About Electrons
Ground state- lowest possible energy state of an electron
Excited state- electron to which energy has been added

30. An electron in its excited state will not stay there very long.
It will release a specific quantity of energy as it “falls” back to its ground state.
Each element releases energy as a unique set of wavelengths.
Metal ions release energy as visible light and can be identified by their emission spectra.