1. Announcements
Lon-capa HW 6 – Type 1 due Monday (11/18) and Type 2 due Wednesday (11/20) by 7pm
“Lab 5: Modern Atomic Theory” write-up due tomorrow in discussion (and text homework)

2. Clicker #1 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.

3. Clicker #2
How many unpaired electrons does sulfur contain in its ground state? (Hint: Draw an orbital diagram.)
A) 0
B) 1
C) 2
D) 3
E) 6

4. Electron configurations and the P. T.

5. 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

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
Hydrogen 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. Clicker #3
Which of the following elements has the largest atomic radius?
A) Ca
B) Al
C) N
D) Sr
E) F

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
Hydrogen 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. Clicker #4
Which of the following elements has the largest ionization energy?
A) P
B) Al
C) Cl
D) Ba
E) K