Transcript Lecture 20

To Do…

Electronic homework (Lon-Capa)


Friday Discussion



HW6 Type 1 due Monday, April 21 by 7 pm;
HW6 Type 2 due Wednesday, April 23 by 7 pm
Chapter 11&12 homework
Turn in Modern Atomic Theory lab write-up
Tuesday lecture

Continue reading Chapter 12
1
General Trend (Atomic Size/Radius)
2
General Trend (Ionization Energy)
3
Clicker Question
Rank the following from smallest to largest
atomic radius.
a)
b)
c)
d)
e)
Rb, Ca, Br, N
Br, N, Rb, Ca
N, Rb, Br, Ca
N, Br, Ca, Rb
Ca, Rb, N, Br
4
Clicker Question
Rank the following from lowest to greatest
ionization energy.
a)
b)
c)
d)
e)
Rb, Ca, Br, N
Br, N, Rb, Ca
N, Rb, Br, Ca
N, Br, Ca, Rb
Ca, Rb, N, Br
5
Overall goal:
Atomic Structure
Chemical Bonding
3D Molecular Structure
Molecular Properties
6
Overall goal:
Atomic Structure
Chemical Bonding
3D Molecular Structure
Molecular Properties
7
Chemical Bond


Force that holds groups of two or
more atoms together and makes
them function as a unit.
Atoms will bond if the molecule is
more stable than the two separated
atoms (lower energy state).
8
Ionic Bonding
9
Al →
3+
Al
+
–
3e
10
Cl +
–
e
→
–
Cl
11
Forming H2
12
Covalent Bonding
13
Clicker Question
Imagine the bond formed in the carbon
monoxide molecule (C-O). Which atom would
you expect to have a greater attraction for the
electrons in the bond?
a) carbon
b) oxygen
c) They have the same attraction (both have n=2 as
highest energy level with an electron).
d) I do not know.
14
Polar Covalent Bonding
15
16
Figure 12-4 p271
Clicker Question
How do lithium, fluorine, and cesium
compare with regard to attraction for an
electron in a shared bond?
a) Li>Cs>F
b) F>Cs>Li
c) F>Li>Cs
d) Li>Cs>F
e) Cs>F>Li
17
Electronegativity
18