1. Electrons
GPS 6

2. Hog Hilton
You are the manager of a prestigious new hotel in downtown Dodgeville—the “Hog Hilton”. It’s just the “snort of town” and you want to keep its reputation a cut above all the other hotels. Your problem is your clientele. They are hogs in the truest sense.
Your major task is to fill rooms in your hotel. The funny shape of your hotel is to accommodate the habits of the hogs. The penthouse is on the first floor and the less desirable rooms are on the top floor.

3. Hog Hilton
You must fill up your hotel keeping the following rules in mind:
Hogs are lazy, so they won’t go to an upper floor until the lower floors are full.
Hogs can’t stand each other except when rule #1 forces them to put up with each other.
If hogs are in the same room, they will face in opposite directions.
They stink, so you can’t put more than two hogs in each room.

4. Hog Hilton 7th Floor 6th Floor 5th Floor 4th Floor 3rd Floor 2nd Floor
 1st Floor

5. Orbital Diagram 3d
 4s
 3p
 3s
 2p
 2s
 1s

6. Hog Hilton vs Orbital Diagram
Monday: 5 hogs
7th floor
6th floor
5th floor
4th floor
3rd floor
2nd floor
1st floor
Orbital Diagram: Boron 3d 4s 3p 3s 2p 2s 1s

7. Hog Hilton Electrons
Hogs are located on floors = electrons in energy levels and sublevels
Each floor has a certain number of rooms = each energy level has a certain number of sublevels and each sublevel has a certain number of orbitals

8. Filling Rules Orbital Diagrams Hog Hilton
Hogs are lazy, so they won’t go to an upper floor until the lower floors are full.
Hogs can’t stand each other except when rule #1 forces them to put up with each other.
If hogs are in the same room, they will face in opposite directions.
They stink, so you can’t put more than two hogs in each room.
Electrons fill the lowest energy level first. This is known as the Aufbau Principle.
Hund’s Rule states that within a sublevel, one electron will go into each of orbital before the electrons will pair up.
According to Pauli Exclusion Principle, when two electrons occupy the same orbital within an energy level and sublevel, they will have opposite spins in order to lower the repulsion between these two negative electrons. There will be no more than two electrons in an orbital.

9. Levels and Sublevels Energy level (n) Sublevels Present 1 s 2 s, p 3
s, p, d 4
s, p, d, f

10. Sublevels, Orbitals, Electrons
Number of Orbitals
Maximum Number of Electrons s 1 2 p 3 6 d 5 10 f 7 14

11. Filling Orbitals
Aufbau principle: the hypothetical process of building an atom (one electron at a time) where electrons fill the lowest energy sublevels first
- give several examples on the board with blank aufbau charts

12. Energy Levels in an Atom
Some sublevels in higher energy levels actually are lower energy than those with lower energy level sublevels
- logically, sublevels fill in n = 1, then n = 2, then n = 3, then n = 4 and so on. However, in reality some of these sublevels overlap with one another.

13. Energy Levels in an Atom
Order for filling sublevels:
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p
Begin from the top with 1s.
Follow the arrows to determine the filling order.

14. Filling Orbitals Hund's rule:
- Every orbital in a sublevel is filled with one electron before any orbital is filled with two electrons
- All electrons in singly occupied orbitals have the same spin.
Only 2 electrons per orbital
- show example with orbitals

15. Filling Orbitals Pauli’s Exclusion Principle
- When two electrons occupy the same orbital, they have opposite spins.
- show example with orbitals

16. Different Orbital Diagram Formats
Boron
1s 2s p
Orbital Diagram: Boron 3d 4s 3p 3s 2p 2s 1s
1s 2s 2p

17. Drawing Orbital Diagrams
Hydrogen (H)
Carbon (C)
Chlorine (Cl)
Neon (Ne)

18. Electron Configurations
Electron configurations represent the way in which electrons are organized in energy levels and sublevels within an atom
This number represents the number of electrons in the sublevel
1s2
This letter represents the sublevel
do several more examples on the board
These are called ground-state electron configurations because the atoms is not excited. If excited by radiation, electrons can bump up to higher energy levels
This number represents the energy level

19. From Orbital Diagram to Electron Configuration
Orbital Diagram: Boron 3d 4s 3p 3s 2p 2s 1s
Electron Configuration: Boron
1s2 2s2 2p1

20. From Orbital Diagram to Electron Configuration
Orbital Diagram: Sulfur 3d 4s 3p 3s 2p 2s 1s
Electron Configuration: Sulfur
1s2 2s2 2p63s2 3p4

21. Orbital Diagrams
1. Given the following orbital diagram, identify the element represented.
2. Give this atom’s electron configuration
Answers:
1. Iron (Fe)
2. 1s22s22p63s23p64s23d6
Or [Ar] 4s23d6
How many valence electrons? 2

22. Orbital Diagrams
1. Given the following orbital diagram, identify the element represented.
2. Give this atom’s electron configuration
Answers:
1. Calcium (Ca)
2. 1s22s22p63s23p64s2

23. Valence Electrons
Valence electrons are the electrons in the outer-most energy level of an atom. These are the electrons involved in chemical reactions
- Do examples on the board – point out valence electrons (the number of electrons in the outer-most energy level)

24. Electron Configurations
What is the electron configuration for Bromine (Br)?
Answer:
1s22s22p63s23p64s23d104p5
What is the valence electron configuration for Bromine (Br)?
Valence are those electrons in the outer-most energy level
show how it’s ok to use notation: [Ar] 4s23d104p5
Add valence electron configurations to atomic model notecards
Answer:
4s24p5

25. Electron Configurations
What is the electron configuration for Rubidium (Rb)?
Answer:
1s22s22p63s23p64s23d104p65s1
What is the valence electron configuration for Rubidium (Rb)?
Valence are those electrons in the outer-most energy level
show how it’s ok to use notation: [Ar] 4s23d104p5
Add valence electron configurations to atomic model notecards
Answer:
5s1

26. Trends Across the Table

27. Energy level and Valence Electrons Trends across the Table

28. Orbital Trends across the Periodic Table

29. Abbreviated Electron Configurations
Electron configurations can be abbreviated (i.e. shortened) Examples: Aluminum (Al) 1s22s22p63s23p1 abbreviated: [Ne]3s23p1 Fluorine (F) 1s22s22p5 abbreviated: [He]2s22p5

30. Abbreviated Electron Configurations
Electron Configuration Calcium
1s2 2s2 2p6 3s2 3p6 4s2
Abbreviated Electron Configuration Calcium
[Ar] 4s2
This represents all the electrons after the noble gas.
This is the last noble gas before calcium.

31. Abbreviated Electron Configurations
What is the abbreviated electron configuration for Bromine (Br)?
Answer:
[Ar]4s23d104p5
Valence are those electrons in the outer-most energy level
show how it’s ok to use notation: [Ar] 4s23d104p5
Add valence electron configurations to atomic model notecards

32. Abbreviated Electron Configurations
What is the abbreviated electron configuration for Rubidium (Rb)?
Answer:
[Kr]5s1
Valence are those electrons in the outer-most energy level
show how it’s ok to use notation: [Ar] 4s23d104p5
Add valence electron configurations to atomic model notecards

33. Chemical Properties of Groups
Octet Rule
an atom that has a full outer-most energy level is unreactive (usually it is full with 8 electrons, but there are some exceptions)
all atoms want to satisfy the octet rule
atoms react with each other in order to satisfy the octet rule
go through the groups and figure out how many electrons each would like to gain or lose to obtain an octet (skipping the transition metals). start with sodium. show that lithium, hydrogen’s outer energy levels can only have two, not eight.
draw sodium’s atomic model on the board. show that it is a neutral atom (11p, 11e). ask: tell me how sodium could satisfy the octet rule. students: could gain 7 electrons or lose one electron. Easier to lose one. now, reevaluate the charge on the atom. 11p, 10e. so, when achieving the octet rule through chemical bonding, sodium tends to lose one electron, leaving it with a positive one charge. this is called forming an ion.
which group, then, satisfies the octet rule and are unreactive? (go through the groups)
Since groups have the same number of valence electrons in their outer energy level, they have similar chemical properties (i.e. they tend to react in similar ways)
Periods have predictable chemical properties because each element across a period has one more electron than the previous element

34. Octet Rule: Forming Bonds
Atoms will gain, lose, or share electrons in order to fulfill the octet rule
When electrons are transferred, ions are formed. Ions are attracted to each other and form ionic bonds
When electrons are shared, covalent bonds are formed

35. Chemical Properties of Groups
Oxidation Numbers

36. Chemical Properties of Groups
Example:
For the following elements, show the ion that it most commonly forms (using proper notation):
Chlorine
Sodium
Nitrogen
Sulfur
Neon
Boron
Magnesium
Lead

37. Oxidation Numbers and Ions
atoms with charges (i.e. not neutral)
Oxidation numbers
indicate the ion that an atom most always forms during chemical reactions
Anion
a negatively charged ion Ex: O2-
Cation
a positively charged ion Ex: Na1+
more examples: ask students to find the oxidation number for various elements
Remember cations are positive because “t” looks like a “+”
Ask if electrons were gained or lost. Also, how many electrons gained or lost?

38. Cation or Anion?
Is the atom on the left a cation or anion?

39. Shapes of Orbitals
Shapes indicate the area in which there is the highest probability of finding an electron at that energy level
Homework: atomic structure worksheet