Rydberg constant

The Rydberg constant sets the characteristic wavenumber scale of spectral lines in hydrogen-like atoms. Its value depends slightly on whether the nucleus is treated as infinitely massive or has finite mass.

Rydberg formula: A formula giving the wavenumbers of spectral lines in hydrogen and hydrogen-like atoms from their principal quantum numbers. It uses the Rydberg constant as the scale factor for transitions between bound states.
Wavenumber: The number of wave cycles per unit distance, commonly expressed in reciprocal centimeters for spectroscopy. The Rydberg constant is expressed as a wavenumber.
Johannes Rydberg: A Swedish physicist who formulated a mathematical relation among spectral lines in the late nineteenth century. His work gave the constant its name and organized observed line positions.
Hydrogen spectroscopy: The measurement and analysis of radiation emitted or absorbed by hydrogen atoms. Measured hydrogen lines allow direct comparisons with predictions using the Rydberg constant.
Rydberg energy: An energy scale equal to the hydrogen ionization energy in the infinite-nuclear-mass approximation. It is the energy counterpart of the wavenumber scale expressed by the Rydberg constant.
Hydrogen spectral series: Groups of hydrogen spectral lines whose transitions share a common lower energy level. Each series follows from the Rydberg formula with a different shared lower level.
Photon: A quantum of electromagnetic radiation with energy proportional to its frequency. An atomic transition emits or absorbs a photon whose wavelength encodes the predicted wavenumber.
Balmer series: The visible series of hydrogen spectral lines ending at the atom's second energy level. Balmer's empirical wavelength pattern preceded the broader Rydberg formula.
Fine-structure constant: A dimensionless constant measuring the strength of electromagnetic interactions. The Rydberg constant and other spectroscopic quantities help determine its value.
Hartree: An atomic unit of energy equal to twice the Rydberg energy. Atomic calculations often express energies in Hartrees rather than Rydberg wavenumbers.

Linked from 9 pages