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

2. Creating a Positive Learning Environment for Everyone
Be respectful of your classmates
Save conversation for clicker portions of lecture
Put cell phones in “airplane” mode
Turn off tablets
Close laptops

3. Announcements
Lon-capa HW 6 – Type 1 due Monday (11/27) and Type 2 due Wednesday (11/29) by 7pm
“Lab 5: Modern Atomic Theory” write-up due Friday in discussion
Textbook HW and Pre-lecture Assignment due as usual

4. Clicker #1
How many of the following statements are true concerning an electron in its ground state?
I. The electron must be in its lowest-energy state.
II. Energy must be applied to the electron in order to excite it.
III. The electron must be located on the nucleus of an atom.
IV. The electron can release energy to obtain a lower ground state.
A) B) 1 C) D) 3 E) 4

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 What comes next in potassium’s electron configuration?
B) 3d1
C) 4s1
D) 4p1
E) 4f1

12. Electron Configurations and the Periodic TableMn

13. Clicker #5
How many unpaired electrons does sulfur contain in its ground state?
A) 0
B) 1
C) 2
D) 3
E) 6

14. 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