Assertion: neptunium | /r/HasSubevent | several studies
Facets:
Source sentences:
text: Although Np 2 O 5 was initially subject to several studies that claimed to produce it with mutually contradictory methods, it was eventually prepared successfully by heating neptunium peroxide to 300-350 °C for 2–3 hours or by heating it under a layer of water in an ampoule at 180 °C.