KnowraPromethiumLinked fromLinked fromThe 5 pages that link to Promethium, each with the reason it gives.All 5Broader topic 3Compared with 2Element discoveryBroader topic: Its discovery relied on isolating and identifying a rare fission product.Henry MoseleyBroader topic: Moseley’s periodic gaps included atomic number 61, later filled by promethium.TechnetiumCompared with: Promethium is the other element between bismuth and uranium with no stable isotopes.Synthetic elementBroader topic: Its discovery in fission products established another element absent from appreciable natural deposits.ThuliumCompared with: Unlike thulium, promethium has no stable naturally occurring isotope.