1. Quantum Chemistry

2. Valence
Edward Frankland ( )
Illustrated for Group 5A Elements

3. When the formulae of inorganic chemical compounds are considered, even a superficial observer is impressed with the general symmetry of their construction. The compounds of nitrogen, phosphorus, antimony, and arsenic, especially, exhibit the tendency of these elements to form compounds containing 3 or 5 atoms of other elements; and it is in these proportions that their affinities are best satisfied: thus in the ternal group we have: NO3, NH3, NI3, NS3, PO3, PH3, PCl3, SbO3, SbH3, SbCl3, AsO3, AsH3, AsCl3, etc.: and in the five-atom group, NO5, NH4O, NH4I, PO5, PH4I, etc. Without offering any hypothesis regarding the cause of this symmetrical grouping of atoms, it is sufficiently evident from the examples just given, that such a tendency or law prevails, and that, no matter what the character of the uniting atoms may be, the combining power of the attracting element, if I may be allowed the term, is always satisfied by the same number of these atoms.
Phil. Trans. Royal Soc.
1852

4. Richard Abegg ( )
Abegg’s Rule
The difference between the maximum
positive and negative valence of an
element is frequently eight.

5. The Development of Quantum Mechanics

6. Nature of Light Christiaan Huygens (1629 – 1695)
Isaac Newton ( )

7. Properties of Waves
Reflection
Refraction

8. Diffraction

9. Interference

10. Properties of Light
Refraction
Reflection

11. Young’s Double Slit Experiment
Thomas Young (1773 – 1829)

12. Laser Source for Double Slit Experiment

13. Interpretation of the Double Slit Results

14. Maxwell’s Equations
James Clerk Maxwell (1831 – 1879)

15. Electromagnetic Radiation
Electromagnetic Spectrum

16. Heinrich Hertz (1857 – 1894)

17. Blackbody Radiation

18. Cavities as Blackbodies

20. The Ultraviolet Catastrophe
Lord Rayleigh
James Jeans

21. Max Planck (1858 – 1947)
After a few weeks of the most strenuous
labor of my life, the darkness lifted and
a new, unimagined prospect began to
dawn.

22. Photoelectric Effect

24. Einstein’s equation was a bold prediction,
Albert Einstein (1879 – 1955)
Robert Millikan ( )
Einstein’s equation was a bold prediction,
for at that time there was no evidence that
Planck’s constant had any applicability
outside of blackbody radiation and there
were no experimental data on the [kinetic
energy] as a function of frequency.
Physics by Paul A. Tipler

25. Millikan’s Photoelectric Data

26. The Double Slit Experiment Revisited

27. Matter Waves
Louis de Broglie (1892 – 1987)
l = h/p

28. Electron Diffraction Observed in 1927
Crystalline Nickel as an Electron Target
L. H. Germer
C. J. Davisson
…studying electron scattering from a nickel target at Bell Laboratories. After heating
the target to remove an oxide coating that had accumulated during an accidental
break in the vacuum system, they found that the scattered-electron intensity as a
function of the scattering angle showed maxima and minima. Their target had
crystallized, and by accident they had observed electron diffraction.
Physics by Paul A. Tipler

29. Electron as “Orbiting” Wave
Constructive Interference
Destructive Interference
(Standing Wave)

30. Quantized “Orbits” Due To Standing Wave Req.

31. Reformulations of Classical Mechanics
Isaac Newton
(1643 – 1727)
Joseph Louis Lagrange
William Hamilton
(1736 – 1813)
(1805 – 1865)

32. Now What? The wave function contains all possible
information about a system, so instead of
speaking of “the state described by the
wave function Y,” we simply say “the
state Y.”
Quantum Chemistry by Ira N. Levine
Erwin Schrodinger (1887 – 1961)

33. What is the Wave Function?
Quantum mechanics does not say that an electron is
distributed over a large region of space as a wave is
distributed. Rather, it is the probability patterns
(wave functions) used to describe the electron’s
motion that behave like waves and satisfy a wave
equation.
Quantum Chemistry by Ira N. Levine
Max Born (1882 – 1970)