neptunium
E463642
Neptunium is a radioactive, synthetic actinide metal and the first transuranium element, used mainly in nuclear research and reactor applications.
All labels observed (1)
| Label | Occurrences |
|---|---|
| neptunium canonical | 3 |
How this entity was disambiguated
This entity first appeared as the object of triple T4707732 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: neptunium Context triple: [Edwin McMillan, co-discovered, neptunium]
-
A.
nobelium
Nobelium is a synthetic, highly radioactive actinide element with atomic number 102, named in honor of Alfred Nobel and used primarily for scientific research.
-
B.
einsteinium
Einsteinium is a synthetic, highly radioactive actinide element named after Albert Einstein and used mainly for scientific research.
-
C.
seaborgium
Seaborgium is a synthetic, highly radioactive transition metal and transactinide element with the symbol Sg and atomic number 106.
-
D.
mendelevium
Mendelevium is a synthetic, radioactive actinide element with atomic number 101, named after Dmitri Mendeleev and produced only in particle accelerators.
-
E.
element meitnerium
Meitnerium is a synthetic, highly radioactive chemical element with atomic number 109, named in honor of physicist Lise Meitner.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: neptunium Target entity description: Neptunium is a radioactive, synthetic actinide metal and the first transuranium element, used mainly in nuclear research and reactor applications.
-
A.
nobelium
Nobelium is a synthetic, highly radioactive actinide element with atomic number 102, named in honor of Alfred Nobel and used primarily for scientific research.
-
B.
einsteinium
Einsteinium is a synthetic, highly radioactive actinide element named after Albert Einstein and used mainly for scientific research.
-
C.
seaborgium
Seaborgium is a synthetic, highly radioactive transition metal and transactinide element with the symbol Sg and atomic number 106.
-
D.
mendelevium
Mendelevium is a synthetic, radioactive actinide element with atomic number 101, named after Dmitri Mendeleev and produced only in particle accelerators.
-
E.
element meitnerium
Meitnerium is a synthetic, highly radioactive chemical element with atomic number 109, named in honor of physicist Lise Meitner.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
actinide
ⓘ
chemical element ⓘ neptunium isotope ⓘ radioactive metal ⓘ transuranium element ⓘ |
| appearance | silvery metallic ⓘ |
| atomicNumber | 93 ⓘ |
| belongsToSeries | actinide series ⓘ |
| block | f-block ⓘ |
| boilingPoint | about 3902 °C ⓘ |
| chemicalSymbol | Np ⓘ |
| corrodesIn | air ⓘ |
| crystalStructure | orthorhombic (alpha phase) ⓘ |
| decayMode | alpha decay ⓘ |
| densityAtRoomTemperature | about 20.45 g/cm³ ⓘ |
| discoveredBy |
Edwin McMillan
NERFINISHED
ⓘ
Philip H. Abelson NERFINISHED ⓘ |
| discoveryPlace | Berkeley Radiation Laboratory NERFINISHED ⓘ |
| discoveryYear | 1940 ⓘ |
| electronConfiguration | [Rn] 5f4 6d1 7s2 ⓘ |
| halfLife | about 2.14 million years ⓘ |
| hasIsotope |
neptunium-235
NERFINISHED
ⓘ
neptunium-236 ⓘ neptunium-237 NERFINISHED ⓘ neptunium-238 NERFINISHED ⓘ neptunium-239 NERFINISHED ⓘ |
| hazard |
chemically toxic heavy metal
ⓘ
radiotoxic ⓘ |
| meltingPoint | about 639 °C ⓘ |
| mostStableIsotope | neptunium-237 NERFINISHED ⓘ |
| namedAfter | Neptune NERFINISHED ⓘ |
| naturalOccurrence | trace amounts in uranium ores ⓘ |
| oxidationState |
+3
ⓘ
+4 ⓘ +5 ⓘ +6 ⓘ +7 ⓘ |
| periodicTableGroup | actinides ⓘ |
| periodicTablePeriod | 7 ⓘ |
| positionRelativeToUranium | immediately after uranium in atomic number ⓘ |
| producedBy |
neutron irradiation of uranium-238
ⓘ
nuclear reactor fuel cycles ⓘ |
| radioactive | true ⓘ |
| standardAtomicWeight | (no stable isotopes) ⓘ |
| synthetic | true ⓘ |
| usedFor |
neutron detection equipment
ⓘ
nuclear research ⓘ production of plutonium-238 ⓘ reactor physics studies ⓘ studies of transuranium chemistry ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: neptunium Description of subject: Neptunium is a radioactive, synthetic actinide metal and the first transuranium element, used mainly in nuclear research and reactor applications.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.