neptunium
E463642
Neptunium is a radioactive, synthetic actinide metal and the first transuranium element, used mainly in nuclear research and reactor applications.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| neptunium-237 | 0 |
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 ⓘ |
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.