TEXTBOOK/CLICKERS

1
Announcements

• TEXTBOOK/CLICKERS
• HOMEWORK- CHAPTER 2 NOW POSTED, DUE 9/6
• LAB THIS WEEK- PRINT EXPERIMENTS, DO PRE-LAB
• CHEMISTRY HELP CENTER

2
Review- Atomic Symbols Isotopes

• ATOM SYMBOLS
• 
  
  
  
• ISOTOPES Have same protons, different
  neutrons
• REVIEW EXAMPLE

3
How many protons does an atom of phosphorus-32
have?

• 32
• 30
• 17
• 15

4
How many electrons does an atom of phosphorus-32
have?

• 32
• 30
• 17
• 15

5
How many neutrons does an atom of phosphorus-32
have?

• 32
• 30
• 17
• 15

6
Its Time For Some Donut Math!

• Dunkin Donuts sells both regular-sized donuts and
  Munchkins
• Lets say that of all the donuts sold
• 78.3 are regular-sized (mass 57g)
• 21.7 are Munchkins (mass 10g)
• What is the weighted average mass of a Dunkin
  Donut?

If Munchkins were more abundant, would the
average mass of a Dunkin Donut go up or down?
7
Isotopes and Average Atomic Mass
A Non-Edible Example Silver has two
isotopes What is the average atomic mass of
Silver?
Isotope Mass (u) Abundance
107Ag 106.905 51.839
109Ag 108.905 48.161
8
Mass Spectrometry Determines MassCharge
Mass spectrometry allows us to determine the
natural abundances of the different isotopes
9
What do these things have in common?
Hormones!
10
Floyd Landis Case

• Landis won 2006 Tour de France
• Tested positive for testosterone doping
• Question 1 Did Landis have an abnormally high
  testosterone level?

11
Isotopes and Steroid Testing

• Question 2 Is the excess testosterone natural
  or synthetic?
• Isotope-ratio mass spectrometry (CIR) used to
  determine the ratio of 13C to 12C in Landis
  testosterone
• Photosynthesis prefers 12C
• C3 plants Strong preference for 12C
• C4 plants Less of a preference for 12C
• Normal diet mixture of C3 and C4 plants
• Synthetic testosterone comes from soy, contains
  less 13C
• 13C12C reduced ? Landis tested positive for
  doping

12
The Periodic Table

• Elements are arranged to highlight common
  properties and trends
• Arrangement reflects microscopic structure of atom

13
The Periodic Table- Groups and Periods
14
Main Group Transition Elements
15
Metals, Nonmetals, Metalloids
16
Groups with Names
17
Periodic Table