1. Introduction

In 1914, J. Frank and G. Hertz performed, what is now considered to be, a classic experiment in modern physics. Their goal was to verify the quantum theory assumptions about the existence of discrete energy levels in atoms and that quantised amounts of energy are transferred in emission and absorption. By accelerating a beam of electrons through a Mercury vapor, they found that when the kinetic energy of the electrons reached about 4.9 eV, the vapor emitted a spectrum line at 254 nm. This experiment laid the foundation for the detailed investigation of the atomic structure of many elements, as well as the development of our current understanding of the electron orbitals.

You will perform three experiments to investigate the atomic structure of Hg and He. The first experiment is the classic Frank-Hertz experiment. The second is a Frank-Hertz-like procedure to investigate atomic processes in Helium. The final experiment is a spectroscopic analysis of the Helium line spectrum.

School of Physics at Georgia Tech 837 State Street, Atlanta, GA 30332-0430 USA, Phone:(404) 894-5201, Fax:(404) 894-9958