1. Announcements Clicker #1
Be respectful – no electronics please!
Announcements
Clicker #1
What is the electron configuration for hydrogen?
A) 1s0
B) 1s1
C) 1s2
D) 1s2s1
E) 1s22s2
Pre/post lecture assignments due as usual Tuesdays & Thursdays at 8:00 am
Textbook homework due tomorrow
Lab on Monday

3. 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.

4. 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

5. 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

6. General Trend (Atomic Size/Radius)

7. Clicker #2
Which of the following elements has the largest atomic radius?
A) Ca
B) Al
C) N
D) Sr
E) F

8. Discussion #1
Of the atoms in the previous example for which would it be easiest to remove an outer electron?
1) H (has fewest electrons) 2) He (is the smallest atom) 3) Li (is the largest atom) 4) Be (has the greatest number of electrons 5) All the same

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 #3
Which of the following elements has the largest ionization energy?
A) P
B) Al
C) Cl
D) Ba
E) K

13. Discussion #2
How many electrons would a neutral atom of lithium have to lose or gain to end up with the same number of electrons as helium?
1) Gain 1 electron 2) Lose 1 electron 3) Gain 2 electrons 4) Lose 2 electrons 5) No change needed (already has the same number of electrons)

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

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

16. 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).

17. Electronegativity

18. Ionic Bonding

19. Ionic Bonding

20. Covalent Bonding

21. Covalent Bonding

22. Polar Covalent Bonding

23. Polar Covalent Bonding

24. Clicker #4 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