• Thomson Cathode-Ray Experiments
In 1897 J.J. Thomson discovered the electron, a negatively charged particle more than two thousand times lighter than a hydrogen atom.

• Millikan Oil Drop Experiment
The 1911 experiment entailed balancing the downward gravitational force with the upward buoyant and electric forces on tiny charged droplets of oil suspended between two metal electrodes.  Since the density of the oil was known, the droplets' masses, and therefore their gravitational and buoyant forces, could be determined from their observed radii.  Using a known electric field, Millikan and Fletcher could determine the charge on oil droplets in mechanical equilibrium.

• Rutherford Scattering Experiments
This experiment (1909 – 1911) showed that the positive matter in atoms was concentrated in an incredibly small volume and gave birth to the idea of the nuclear atom.

• Frank-Hertz Experiment
(1914) Electrons were accelerated by a voltage toward a positively charged grid in a glass envelope filled with mercury vapor.  Past the grid was a collection plate held at a small negative voltage with respect to the grid.  The values of accelerating voltage where the current dropped gave a measure of the energy necessary to force an electron to an excited state.

• Stern-Gerlach Experiment
The Stern–Gerlach experiment (1921) was meant to test the Bohr–Sommerfeld hypothesis that the direction of the angular momentum of a silver atom is quantized.  It later (1925) confirmed the quantization of the spin and magnetic moment of the electron.

• Compton Scattering Experiment
(1923) X-rays are scattered from (nearly) free electrons.  To understand Compton scattering we must think of photons as particles.

• Davisson-Germer Experiment
This experiment (1926) demonstrated the wave nature of the electron, confirming the earlier hypothesis of deBroglie.

Experimental apparatus and methods

• Counters
Common devices, counting statistics, dead time
• Data analysis
Error propagation, graphing, cross-sections, decay and attenuation
• Electronics
Diodes, transistors, op-amps

Example Problems:  (Solutions)

Problem 1:

Problem 2:

Problem 3:

Problem 4:

Problem 5:

Problem 6:

Problem 7:

Problem 8:

Problem 9:

Problem 10: