🌐EnglishEnglishEspañolItalianoPortuguêsРусский中文日本語EntityQ2605552· pop 9· linked from 11 articlesRydberg–Ritz combination principleprinciple of spectral linesAvailable in 9 languagesEspañol日本語РусскийPortuguêsItalianoArmenianFinnishUkrainianvia Wikidata sitelinks · CC0ConnectionshydrogenEntityQ7085EntityCategoriesEmission spectroscopyOld quantum theory