A 1925, ya lura da rauni radioactivity a cikin wani samfurin na potassium, wani alkali karfe, da kuma ba daidai ba kammala cewa eka-caesium aka gurbata da samfurin (radioactivity daga samfurin ya daga cikin halitta potassium radioisotope, potassium-40). Ya sa'an nan kuma buga a thesis a kan tsinkaya daga cikin kaddarorin na eka-caesium, a cikin abin da ya mai suna russium kashi bayan gida kasar: Passage: Soviet chemist D. K. Dobroserdov shi ne na farko da masanin kimiyya da ya yi iƙirarin sun samu eka-caesium, ko francium. A 1925, ya lura da rauni radioactivity a cikin wani samfurin na potassium, wani alkali karfe, da kuma ba daidai ba kammala da cewa eka-caesium aka gurbata da samfurin (radioactivity daga samfurin ya daga cikin halitta potassium radioisotope, potassium-40). A 1936, da suka yi amfani da aka gano a cikin wani lokaci da aka gano a cikin wani samfurin na potassium, wanda aka gano a cikin wani lokaci da aka gano alamu da aka
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