Nature of Light

Young Einstein

Particle (photon)Wave

Wave-Particle Duality(What does this mean?)

Rutherford’s Gold Foil Experiment

One day Geiger came to and said, “Don’t you think that young Marsden,whom I am training in radioactive methods, ought to begin a small research?” Now I had thought that too, so I said, “Why not let himsee if any alpha particles can be scattered through a large angle?” I maytell you in confidence that I did not believe that there would be, sincewe knew the alpha particle was a very fast massive particle, with a greatdeal of energy, and you could show that if the scattering was due to theaccumulated effect of a number of small scatterings the chance of an alphaparticle being scattered backward was very small.

Ernest Rutherford (1871 – 1937)

Then I remember two or three days later Geiger coming to me in great excitement and saying, “We have been able to get some ofthe alpha particles coming backwards…” It was quite the mostincredible event that has ever happened to me in my life. It wasalmost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it cam back and hit you.

http://waowen.screaming.net/revision/nuclear/rsanim.htm

Atomic Spectra

Hydrogen Helium Mercury Neon

The Hydrogen Spectrum

Johann Jakob Balmer (1825 - 1898)

Johannes Rydberg (1854 – 1919)

WalterRitz (1878 – 1909)

Ritz Combination PrincipleThe sum of the frequencies of two spectral lines equalsthe frequency of a third.

Lyman Lines Balmer Lines Paschen Lines

The Complete Hydrogen Spectrum

Energy Diagram for the Hydrogen Atom

Bohr Model of the Hydrogen Atom

Neils Bohr (1885 – 1962)

Matter Waves

Louis de Broglie (1892 – 1987)

= h/p

L. H. Germer C. J. Davisson

Crystalline Nickel as an Electron Target

…studying electron scattering from a nickel target at Bell Laboratories. After heatingthe 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 hadcrystallized, and by accident they had observed electron diffraction.

Physics by Paul A. Tipler

Electron Diffraction Observed in 1927

Electron as “Orbiting” Wave

Constructive Interference Destructive Interference(Standing Wave)

http://www.youtube.com/watch?v=_S7-PDF6Vzc

Quantized “Orbits” Due To Standing Wave Req.

Now What?

Erwin Schrodinger (1887 – 1961)

The wave function contains all possibleinformation about a system, so instead of speaking of “the state described by thewave function ,” we simply say “thestate .”

Quantum Chemistry by Ira N. Levine

What is the Wave Function?

Max Born (1882 – 1970)

Quantum mechanics does not say that an electron isdistributed over a large region of space as a wave isdistributed. Rather, it is the probability patterns(wave functions) used to describe the electron’smotion that behave like waves and satisfy a waveequation.

Quantum Chemistry by Ira N. Levine