1. Be respectful – no electronics please!
Announcements
Pre/post lecture assignments due as usual Tuesdays & Thursdays at 8:00 am
Textbook homework due tomorrow
Lab on Monday

2. Electron Configuration: The Finer Points
Name that element:
1s22s22p63s23p3
Phosphorous
Valence Electrons
Highest or outermost energy level electrons
Where the chemistry happens! 
Look at principal quantum level n
Look at group or family

3. Number of Valence Electrons in…?Li K
[Ne]3s1 1 1 1

4. Clicker #1
How many unpaired electrons are in a neutral ground state atom of phosphorus? A) 1 B) 3 C) 5 D) 7 E) 15

5. Electron Configuration: The Finer Points
Name that element, in an excited state!
1s22s13s1
Number of unpaired electrons in this excited state?
Number of unpaired electrons in ground state?
Beryllium 2

6. Atomic Radius (Size) Increases down a group Hydrogen
Francium
Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels

7. Atomic Radius (Size)
Decreases across a row (period) – outer electrons in the same energy level
Lithium Fluorine
DECREASES!
More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly, pulling them in and shrinking the size.

8. General Trend (Atomic Size/Radius)

9. Ionization Energy Decreases down a group Hydrogen
Francium
Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels. Electrons are not as tightly bound by the nucleus at higher energy levels so it takes less energy to remove an outer electron.

10. Ionization Energy
Increases across a row (period) – outer electrons in the same energy level
Lithium Fluorine
INCREASES!
More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly and pulling them in closer to the nucleus, requiring MORE energy to remove an outer electron.

11. General Trend (Ionization Energy)

12. Clicker #2
Of the following elements, which has the largest radius, and which has the largest first ionization energy?
P, Al, Cl, Ba, Ca
Radius
Ionization Energy a) Cl Ba b) c) Ca d) Al e)

13. Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure
Molecular Properties

14. Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure
Molecular Properties

15. Bond (Intramolecular)
Force that holds groups of two or more atoms together and makes them function as a unit.
Bond is more stable than the two separated atoms (lower energy state).

16. Electronegativity

17. Ionic Bonding

18. Ionic Bonding

19. Covalent Bonding

20. Covalent Bonding

21. Polar Covalent Bonding

22. Polar Covalent Bonding

23. Clicker #3 Rank the following bonds from least polar to most polar:
Si-Cl P-Cl Mg-Cl S-Cl
A) S-Cl, P-Cl, Mg-Cl, Si-Cl
B) P-Cl, S-Cl, Si-Cl, Mg-Cl
C) Mg-Cl, Si-Cl, P-Cl, S-Cl
D) Mg-Cl, S-Cl, P-Cl, Si-Cl
E) S-Cl, P-Cl, Si-Cl, Mg-Cl