Sequanium
Open-knowledge reference entry
Sequanium was the proposed name for a new element that Romanian physicist Horia Hulubei reported he had discovered in 1939. The name derived from the Latin word Sequana for the river Seine running through Paris where Hulubei worked at that time.
Hulubei thought he had discovered element 93 in a tantalite sample from the French region Haute-Vienne. Element 93 was synthesised in 1940 and named neptunium. It does in fact occur in nature in trace amounts, but it is not commonly believed that Hulubei actually discovered it.
The public source identifies “Sequanium” as open-knowledge reference entry. This brief keeps that definition visible, then builds a research path around Sequanium, Open-knowledge and entry.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Sequanium”, the useful work is to connect “open-knowledge reference entry” to the records capable of establishing context and consequence.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 18, 2026. The linked authority identifier is Q7452431. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1939 and 1940.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Sequanium”, its source revision and the description used here.
- Expand the search: follow Sequanium primary sources, Sequanium archive and Sequanium research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Sequanium”?
- Which cited source is closest to the event, object or claim?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Sequanium” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.