/kloc-At the end of 0/9, many scientists paid attention to atomic spectrum and atomic structure, and Ridderborg was one of them. His study of spectra stems from his interest in the periodic table of elements. Since 1890, he has been engaged in the research on the physical properties, chemical properties and structures of elements, and published the paper "Study on the Emission Spectrum Structure of Chemical Elements". He imagined that the spectral line of an element consists of three different types of series, one is the sharp line system in the visible region, the other is the diffuse line system in the near infrared region, and the third is the most important line system composed of ultraviolet rays.

At the same time, Rydberg personally observed the spectral lines of some elements and collected a lot of spectral data from his peers, especially the spectral line wavelengths of lithium, sodium, potassium, magnesium, zinc, cadmium, mercury, aluminum and other elements, which provided an important basis for him to summarize the spectral formula. Facing the chaotic and complicated spectral data, he devoted himself to seeking the significance of various spectral lines emitted by various elements. The key to Rydberg's success is to use the reciprocal of wavelength (wave number) to represent spectral lines, which has been proposed by predecessors (such as 187 1 annual Steiner, etc.). The advantage of using this scale is that the spectral line system can be expressed as equidistant, which is closer to the scene directly seen by the spectrometer. So he summed up the law of spectrum: "Every term of spectrum is a function of successive integers, and each spectrum can be approximately expressed by the following formula, where n is the wave number, m is a positive integer, and n0= 10972 1.6 is the * * constant of all spectra. It can be seen from the formula that n0 represents the extreme value of the wave number n trend when m becomes infinite. This is Rydberg's spectroscopy formula.