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

2. Be respectful – no electronics please!
Announcements
Pre/post lecture assignments due as usual Tuesdays & Thursdays at 8:00 am
Textbook homework due Friday
How many electrons are present in a neutral atom of carbon? 3 4 5 6

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

4. Take Homes: Atomic Structure
A brief progression:
Dalton
Bohr
Thomson &
Thompson
Rutherford

5. Electrons Electrons are most likely to be found near the nucleus
Electrons could be anywhere (very far even)
We do not know how the electron moves
ORBITALS = regions of 90% probability

6. Clicker #2
How many electrons can fit in a set of d orbitals in the third energy level? How many electrons can fit in a set of f orbitals in the fourth energy level?
A) 1; 1
B) 2; 2
C) 5; 7
D) 10; 14
E) 15; 28

7. Electron Configurations and the Periodic TableLi Be

8. Clicker #3 Why is diagram #1 preferred over diagram #2?
diagram # diagram #2
A) Because spreading out between orbitals of equal energy will minimize electron-electron repulsions.
B) Because each orbital “wants” an electron and this way two of the orbitals will be “happy”.
C) Because this way there are fewer electrons in the element so the nucleus can have a greater positively charged pull overall.
D) Because this arrangement allows us to better predict the wavelength (and thus color) of light that will be emitted to return to its ground state.

9. Electron Configurations and the Periodic TableNa

10. Electron Configurations and the Periodic TableK

11. Clicker #4
Use the noble gas shorthand method to give the electron configuration for this element.
Determine the number of unpaired electrons an energy diagram of this element is likely to contain.
A) 0 B) 1 C) 2 D) 3 E) 6

12. Electron Configurations and the Periodic TableMn

13. Valence Electrons Highest or outermost energy level electrons
Where the chemistry happens! 
Look at principal quantum level n
Sulfur: 1s22s22p63s23p4
Valence electrons are in n = 3 level
Valence electrons = = 6 electrons

14. Cat Video and Alkali Metals
(minute 1:00)