Balmer series / Determination of Rydberg's constant

Principle

The spectral lines of hydrogen and mercury are examined by means of a diffraction grating. The known spectral lines of Hg are used to determine the grating constant. The wave lengths of the visible lines of the Balmer series of H are measured.

Benefits

• Simple setup for high ranking experiments
• Fundamental Rydberg's constant determined within an hour
• HV power supply with high safety standards makes experimentation safe

Tasks

1. Determination of the diffraction grating constant by means of the Hg spectrum.
2. Determination of the visible lines of the Balmer series in the H spectrum, of Rydberg's constant and of the energy levels.

Learning objectives

• Diffraction image of a diffraction grating
• Visible spectral range
• Single electron atom
• Atomic model according to Bohr
• Lyman-, Paschen-, Brackett and Pfund Series
• Energy level
• Planck's constant
• Binding energy