1. Electron Configuration

2. Atomic Models Bohr Model Rutherford Model
Defined (__________) shells of different energy levels
Rutherford Model
Electrons are found anywhere in the “________” region around the nucleus

3. Current Theory: Quantum Mechanical Model
Rutherford’s electron cloud idea is still used, but the cloud is divided into specific regions (shapes) called _______________.
Hybrid of the Bohr/Rutherford models

4. Bohr’s Contribution
We also still need to account for Bohr’s light ____________ observations that suggest quantized energy levels though…
So, electrons are now theorized to jump between _________________ (clouds) instead of energy levels.

5. Diagram of how Probability Maps Are a Hybrid of Rutherford’s & Bohr’s Models

6. How did we map the electron cloud shapes?
The clouds represent __________________ distribution maps for electron ___________________
We can specify the _____________ of an electron (emission), but not a well-defined _______________ at any given instant (no uniform circular paths).
Instead, the electron’s position is described in terms of an orbital, a probability distribution ______ showing ____________ the electron is likely to be found at any given moment.

7. Schrödinger’s Electron Orbitals
Electron orbitals describe a region around the nucleus where electrons are likely to be found at any given moment.

8. Electron Orbitals (clouds)
Each orbital can only hold __ electrons…why?
Same charge = _______________!
But, they are theorized have opposite magnetic ________ (N & S) due to ___________ in opposite directions.
Short hand:
Written as 2 ___________

9. Electron Energy Levels vs. Orbitals
In the old Bohr model, electrons occupy quantized energy levels
Now, we are saying that each energy level is made up of a certain number of ________ (clouds).
Each orbital can only hold 2e-
Therefore each energy level can only hold a specific ___________ of electrons, based on how many ___________ make it up.

10. Electron Configuration
Within each energy level, there are specific orbitals that electrons occupy.
Electron orbitals are categorized based on the __________________ (shell 1,2,3, etc) and ___________ shape (s, p, d, f)
S-sublevels can hold __ electrons
(made of __ orbital)
P-sublevels can hold __ electrons
(made of __ orbitals)
D-sublevels can hold __ electrons
F-sublevels can hold __ electrons

11. How Sublevels (s, p, d, f) are made of Orbitals

12. Hierarchy of Energy Levels, Sub-levels, and orbitals

13. Filling Orbitals
Due to the _____________ of like charges, electrons will ______ orbitals in a certain order and in a specific ____________.

14. Tying It All to the Periodic Table
2 Ways to predict e- configuration: Diagonal Rule or Periodic Table
Regions of the periodic table correspond with specific __________________!
Following the table from left to right, you will give the correct ________ e- occupy orbitals in

15. Electron Configuration Examples
Nitrogen (7 electrons)
2 in ___ sublevel (1 orbital)
3 in ___ sublevel (3 orbitals)
Electron Configuration =
Coefficient = _______________ orbitals are found in.
Letter = __________ of the orbitals
Exponent = _____________ of electrons occupying the orbitals

16. Try It!
Titanium (Ti)
Sulfur (S)
Tantalum (Ta)

17. How Did You Do? Titanium (Ti) 22 e- 1s22s22p63s23p64s23d2
Sulfur (S) 16 e-
1s22s22p63s23p4
Tantalum (Ta) 73 e-
1s22s22p63s23p64s23d104p65s24d105p6
6s24f145d3

18. Excitation & Emission – Old Theory
Electrons can jump from its ground state to another energy level when energy is added to an atom.
______________ occurs when an electron ________ energy, causing it to jump up to a higher energy level
___________ occurs when an electron ___________ energy, dropping it back down to its original lower energy level

19. New Theory: Jumping Sublevels
Adding energy to an atom (excitation) may cause an electron to jump to a higher _______________
It takes more energy to move between lower energy sublevels than higher ones. Why? (Think atomic structure and shell location)
Removing energy may cause an electron to jump back to its ___________________ (emission)
Emission of energy results in the emission of electromagnetic energy of varying wavelengths depending on the amount of energy given off.

20. Valence vs Core Electrons
Valence electrons are those found in the _________________ energy level.
Core electrons are the electrons occupying the orbitals of ____________ energy levels.
Using Bohr model: how many core/valence electrons for Cl?

21. Chlorine Bohr Model Total e- : 17 Valence e- : 7 Core e- : 10
Note that you can use the electron configuration to find the electrons in the outer-most energy level (level 3), giving you the number of valence electrons (2+5 = 7)