Atoms, Molecules and Quantum Mechanics:

1
Atoms, Molecules and Quantum Mechanics

• The Universal Building Blocks

2
Heisenberg Uncertainty

• ?p ?x h / 4p
• ?E ?t h / 4p
• Cannot know all about a particle (position and
  momentum)

3
Discreet Energy Levels

• Used to explain line spectra
• Used to build lasers

4
Periodic Table

• Atomic Size, Ionic Size

5
Periodic Table Questions

• Periodicity
• NaCl, KCl, MgCl2, BaCl2
• NH3, H2O, HF, Ne
• Size, Bonding

6
Chemical Bonding

• Chemical Bonds and Quantum Mechanics

7
Types of Bonds

• Covalent
• Locally Shared Electrons
• Ionic
• Gained or Lost Electrons
• Metallic
• Long range delocalization

8
Covalent Bonding

• Why are noble gases inert?
• Consider orbitals
• He 1s2
• F 1s2 2s2 2p5
• Ne 1s2 2s2 2p6
• Ar 1s2 2s2 2p6 3s2 3p6

9
Covalent Bonding

• H H gives H2
• O 2 H give H2O
• C 4 H gives CH4

10
Ionic Bonding

• NaCl, MgCl2, Na2SO4
• Why is Na and Mg2?
• Why is Cl and SO42?

11
Why does Salt Dissolve?

• Solvation (hydration)

12
Metallic Bonds

• Ion cores stay put
• Electrons act as bath of freely moving particles

13
Fuel Cell Car

• Electron Transport
• 2H2 ? 4H 4e
• O2 4e ? 2O2
• Net Reaction2 H2 O2 ? H2O ENERGY