This page covers the absorption and emission line spectra of hydrogen, focusing on the Balmer series as described by Johann Balmer. It mentions historical contributions from Isaac Newton, Anders Ångst...This page covers the absorption and emission line spectra of hydrogen, focusing on the Balmer series as described by Johann Balmer. It mentions historical contributions from Isaac Newton, Anders Ångström, William Wollaston, and Joseph von Fraunhofer. The text details how line spectra reveal atomic structure and discusses the relationship between wavelength and frequency using wavenumbers.