Neptunium (Np)

Neptunium is the 93rd element in the periodic table and has a symbol of Np and atomic number of 93. It has an atomic weight of (237) and a mass number of 219. Neptunium has ninety-three protons and one hundred twenty-six neutrons in its nucleus, and ninety-three electrons in seven shells. It is located in group Actinides, period seven and block f of the periodic table. Radioactive metallic transuranic element, belongs to the actinoids. Np-237, the most stable isotope, has a half-life of 2.2*10^6 years and is a by product of nuclear reactors. The other known isotopes have mass numbers 229 through 236, and 238 through 241. Np-236 has a half-life of 5*10^3 years. First produced by Edwin M. McMillan and P.H. Abelson in 1940.

Atomic Number	93
Atomic Weight	237
Mass Number	219

Group
Period	7
Block	f

Protons	93 p⁺
Neutrons	126 n⁰
Electrons	93 e^-

Properties

Physical Properties
Atomic Radius	175 pm 281 pm
Molar Volume	21.1 cm³/mol
Covalent Radius	171 pm 136 pm 116 pm 190 pm
Metallic Radius
Ionic Radius	110 pm 101 pm 87 pm 98 pm 75 pm 72 pm 71 pm 117.8 pm
Crystal Radius	124 pm 115 pm 101 pm 112 pm 89 pm 86 pm 85 pm 131.8 pm
Van der Waals Radius	239 pm 252 pm 342.4 pm
Density	20.2 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy	6.2655 eV/particle 11.5 eV/particle 19.7 eV/particle 33.8 eV/particle 48 eV/particle 65 eV/particle 92 eV/particle 107 eV/particle 121 eV/particle 136 eV/particle 151 eV/particle 179 eV/particle 196 eV/particle 233 eV/particle 252 eV/particle 355 eV/particle 382 eV/particle 408 eV/particle 438 eV/particle 466 eV/particle 495 eV/particle 535 eV/particle 565 eV/particle 596 eV/particle 626 eV/particle 770 eV/particle 810 eV/particle 850 eV/particle 880 eV/particle 980 eV/particle 1,020 eV/particle 1,130 eV/particle 1,170 eV/particle 1,280 eV/particle 1,360 eV/particle 1,430 eV/particle 1,510 eV/particle 1,590 eV/particle 1,670 eV/particle 1,740 eV/particle 1,820 eV/particle 1,910 eV/particle 1,990 eV/particle 2,070 eV/particle 2,140 eV/particle 2,200 eV/particle 2,310 eV/particle 2,675 eV/particle 2,745 eV/particle 2,817 eV/particle 2,894 eV/particle 2,969 eV/particle 3,041 eV/particle 3,181 eV/particle 3,255 eV/particle 3,338 eV/particle 3,413 eV/particle 3,718 eV/particle 3,792 eV/particle 3,872 eV/particle 3,947 eV/particle 4,353 eV/particle 4,441 eV/particle 4,658 eV/particle 4,744 eV/particle 7,610 eV/particle 7,770 eV/particle 7,950 eV/particle 8,130 eV/particle 8,310 eV/particle 8,480 eV/particle 8,890 eV/particle 9,070 eV/particle 9,270 eV/particle 9,450 eV/particle 9,970 eV/particle 10,130 eV/particle 10,300 eV/particle 10,460 eV/particle 11,740 eV/particle 11,930 eV/particle 12,320 eV/particle 12,500 eV/particle 25,870 eV/particle 26,300 eV/particle 26,770 eV/particle 27,210 eV/particle 31,910 eV/particle 32,500 eV/particle 33,300 eV/particle 33,722.2 eV/particle 132,901.8 eV/particle 135,202 eV/particle

Heat of Vaporization	336 kJ/mol
Heat of Fusion	9.6 kJ/mol
Heat of Formation	464.8 kJ/mol
Electrons
Electron Shells	2, 8, 18, 32, 22, 9, 2

Valence Electrons	2 ⓘ

Electron Configuration	[Rn] 5f⁴ 6d¹ 7s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 5f⁴ 6d¹ 7s²

Oxidation States	2, 3, 4, 5, 6, 7
Electronegativity	0.14265 1.3
Electrophilicity Index
States of Matter
Phase	Solid
Gas Phase
Boiling Point
Melting Point	917.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Neptunium is a Silver. Np has a CPK of #ffffff, Jmol of #0080ff, and MOLCAS GV of #0080ff. The Appearance of Element 93 is silvery metallic.
Color	Silver #ffffff #0080ff #0080ff
Appearance	silvery metallic
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion
Molar Heat Capacity
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	0.83 MS/m
Electrical Resistivity	0.0000012 m Ω
Superconducting Point
Magnetism
Type
Magnetic Susceptibility (Mass)
Magnetic Susceptibility (Molar)
Magnetic Susceptibility (Volume)
Magnetic Ordering
Curie Point
Neel Point
Structure
The Crystal Structure of Neptunium is ORC. The lattice constant of Np is 4.72 Å. The lattice angles of Element 93 are π/2, π/2, π/2.
Crystal Structure	Simple Orthorhombic (ORC)
Lattice Constant	4.72 Å
Lattice Angles	π/2, π/2, π/2
Mechanical Properties

Hardness
Bulk Modulus
Shear Modulus
Young's Modulus
Poisson Ratio
Speed of Sound
Classification
The Glawe Number of Neptunium is 37. The Mendeleev Number of Np is 22. The Pettifor Number of Element 93 is 44. The Goldschmidt Class of Neptunium (Np) is synthetic.
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	37
Mendeleev Number	22
Pettifor Number	44
Geochemical Class
Goldschmidt Class	synthetic
Other
The Dipole Polarizability of Neptunium is 151 plus or minus 20 a₀. The Allotropes of Np is . The Neutron Cross Section of Element 93 is 180. The Quantum Numbers of Neptunium (Np) is 6L11/2. The Space Group of Neptunium is 62 (Pnma).
Gas Basicity
Dipole Polarizability	151 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section	180
Neutron Mass Absorption
Quantum Numbers	6L11/2
Space Group	62 (Pnma)

Isotopes of Neptunium

Stable Isotopes	0
Unstable Isotopes	27
Radioactive Isotopes	27

²¹⁹Np

Mass Number	219
Neutron Number	126
Relative Atomic Mass	219.031601865 ± 0.000098732 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	570 ± 450 us
Spin	9/2
Quadrupole Moment
Discovery Year	2015
Parity	-

Decay Mode	Intensity
α (α emission)	100%

²²⁰Np

Mass Number	220
Neutron Number	127
Relative Atomic Mass	220.03271628 ± 0.000032977 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	29 ± 11 ns
Spin	1
Quadrupole Moment
Discovery Year	2019
Parity	-

Decay Mode	Intensity
α (α emission)	100%

²²¹Np

Mass Number	221
Neutron Number	128
Relative Atomic Mass	221.03211 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	9/2
Quadrupole Moment
Discovery Year
Parity	-

Decay Mode	Intensity
α (α emission)

²²²Np

Mass Number	222
Neutron Number	129
Relative Atomic Mass	222.033574706 ± 0.000040849 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	480 ± 190 ns
Spin	1
Quadrupole Moment
Discovery Year	2020
Parity	-

Decay Mode	Intensity
α (α emission)	100%

²²³Np

Mass Number	223
Neutron Number	130
Relative Atomic Mass	223.03291334 ± 0.000088956 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.5 ± 0.8 us
Spin	9/2
Quadrupole Moment
Discovery Year	2017
Parity	-

Decay Mode	Intensity
α (α emission)	100%

²²⁴Np

Mass Number	224
Neutron Number	131
Relative Atomic Mass	224.03438803 ± 0.000031052 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	48 ± 19 us
Spin	2
Quadrupole Moment
Discovery Year	2018
Parity	-

Decay Mode	Intensity
α (α emission)	100%

²²⁵Np

Mass Number	225
Neutron Number	132
Relative Atomic Mass	225.033943422 ± 0.000098355 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	6.5 ± 3.5 ms
Spin	9/2
Quadrupole Moment
Discovery Year	1994
Parity	-

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

²²⁶Np

Mass Number	226
Neutron Number	133
Relative Atomic Mass	226.035230364 ± 0.000109568 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	35 ± 10 ms
Spin
Quadrupole Moment
Discovery Year	1990
Parity

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

²²⁷Np

Mass Number	227
Neutron Number	134
Relative Atomic Mass	227.034975012 ± 0.000082651 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	510 ± 60 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1990
Parity	+

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

²²⁸Np

Mass Number	228
Neutron Number	135
Relative Atomic Mass	228.036313 ± 0.000108 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	61.4 ± 1.4 s
Spin	4
Quadrupole Moment
Discovery Year	1994
Parity	+

Decay Mode	Intensity
ϵ (electron capture)	59%
α (α emission)	41%
β⁺ SF (β⁺-delayed fission)	0.012%

²²⁹Np

Mass Number	229
Neutron Number	136
Relative Atomic Mass	229.036287269 ± 0.000108618 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	4 ± 0.18 m
Spin	5/2
Quadrupole Moment
Discovery Year	1968
Parity	+

Decay Mode	Intensity
α (α emission)	68%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

²³⁰Np

Mass Number	230
Neutron Number	137
Relative Atomic Mass	230.03782806 ± 0.000059051 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	4.6 ± 0.3 m
Spin	4
Quadrupole Moment
Discovery Year	1968
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	97%
α (α emission)	3%

²³¹Np

Mass Number	231
Neutron Number	138
Relative Atomic Mass	231.038243598 ± 0.000054916 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	48.8 ± 0.2 m
Spin	5/2
Quadrupole Moment
Discovery Year	1950
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	98%
α (α emission)	2%

²³²Np

Mass Number	232
Neutron Number	139
Relative Atomic Mass	232.040107 ± 0.000107 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	14.7 ± 0.3 m
Spin	5
Quadrupole Moment
Discovery Year	1950
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)

²³³Np

Mass Number	233
Neutron Number	140
Relative Atomic Mass	233.040739421 ± 0.000054729 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	36.2 ± 0.1 m
Spin	5/2
Quadrupole Moment
Discovery Year	1950
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.0007%

²³⁴Np

Mass Number	234
Neutron Number	141
Relative Atomic Mass	234.042893245 ± 0.000009014 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	4.4 ± 0.1 d
Spin	0
Quadrupole Moment	0
Discovery Year	1949
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

²³⁵Np

Mass Number	235
Neutron Number	142
Relative Atomic Mass	235.044061518 ± 0.00000149 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	396.1 ± 1.2 d
Spin	5/2
Quadrupole Moment
Discovery Year	1949
Parity	+

Decay Mode	Intensity
ϵ (electron capture)	99.9974%
α (α emission)	0.0026%

²³⁶Np

Mass Number	236
Neutron Number	143
Relative Atomic Mass	236.046568296 ± 0.000054129 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	153 ± 5 ky
Spin	6
Quadrupole Moment
Discovery Year	1949
Parity	-

Decay Mode	Intensity
ϵ (electron capture)	86.3%
β⁻ (β⁻ decay)	13.5%
α (α emission)	0.16%

²³⁷Np

Mass Number	237
Neutron Number	144
Relative Atomic Mass	237.04817164 ± 0.000001201 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.144 ± 0.007 My
Spin	5/2
Quadrupole Moment	3.886 ± 0.006
Discovery Year	1948
Parity	+

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	2%
30Mg	4%

²³⁸Np

Mass Number	238
Neutron Number	145
Relative Atomic Mass	238.050944603 ± 0.00000122 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.099 ± 0.002 d
Spin	2
Quadrupole Moment
Discovery Year	1949
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²³⁹Np

Mass Number	239
Neutron Number	146
Relative Atomic Mass	239.052937538 ± 0.000001406 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.356 ± 0.003 d
Spin	5/2
Quadrupole Moment
Discovery Year	1940
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
α (α emission)

²⁴⁰Np

Mass Number	240
Neutron Number	147
Relative Atomic Mass	240.056163778 ± 0.000018284 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	61.9 ± 0.2 m
Spin	5
Quadrupole Moment
Discovery Year	1953
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴¹Np

Mass Number	241
Neutron Number	148
Relative Atomic Mass	241.058309671 ± 0.00010736 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	13.9 ± 0.2 m
Spin	5/2
Quadrupole Moment
Discovery Year	1959
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
α (α emission)

²⁴²Np

Mass Number	242
Neutron Number	149
Relative Atomic Mass	242.061639548 ± 0.000214712 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.2 ± 0.2 m
Spin	1
Quadrupole Moment
Discovery Year	1979
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴³Np

Mass Number	243
Neutron Number	150
Relative Atomic Mass	243.064204 ± 0.000034 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	1.85 ± 0.15 m
Spin	5/2
Quadrupole Moment
Discovery Year	1979
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴⁴Np

Mass Number	244
Neutron Number	151
Relative Atomic Mass	244.067891 ± 0.000107 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.29 ± 0.16 m
Spin	7
Quadrupole Moment
Discovery Year	1987
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴⁵Np

Mass Number	245
Neutron Number	152
Relative Atomic Mass	245.070693 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)

History

Neptunium was the first synthetic transuranium element of the actinide series to be discovered. Neptunium was first produced by Edwin McMillan and Philip H. Abelson in 1940 at Berkeley Radiation Laboratory of the University of California. The team produced the neptunium isotope ²³⁹Np by bombarding uranium with slow moving neutrons. Named after the planet Neptune

Discoverers	E.M. McMillan, P.H. Abelson
Discovery Location	United States
Discovery Year	1940
Etymology (Name Origin)	Named for the planet Neptune.
Pronunciation	nep-TOO-ni-em (English)

Neptunium is harmful due to its radioactivity

Neptunium is obtained as a by-product from nuclear reactors

Uses

Neptunium is used mainly for research purposes. When bombarded with neutrons ²³⁷Np is used to produce ²³⁸Pu which is used for spacecraft generators and terrestrial navigation beacons. ²³⁷Np is used in devices for detecting high-energy neutrons. It has no significant commercial applications.

Sources

Produced by bombarding uranium with slow neutrons.

Abundance
Abundance in Earth's crust
Natural Abundance (Oceans)
Natural Abundance (Human Body)	0 %
Natural Abundance (Meteor)	0 %
Natural Abundance (Sun)	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Also Known As

Np
element 93
93Np

Translations

Frenchneptunium
Norwegian Bokmålneptunium
GermanNeptunium
Italiannettunio
Dutchneptunium
Norwegian Nynorskneptunium
Danishneptunium
Swedishneptunium
Amharicኔፕቲዩኒየም
Arabicنبتونيوم
AzerbaijaniNeptunium
BelarusianНептуній
Bulgarianнептуний
Banglaনেপচুনিয়াম
Bosnianneptunij
Catalanneptuni
CherokeeᏁᏩᏚᏂᎥᎻ
CorsicanNettuniu
Czechneptunium
ChuvashНептуни
WelshNeptwniwm
Greekποσειδώνιο
Esperantoneptunio
Spanishneptunio
Estonianneptuunium
Basqueneptunio
Persianنپتونیوم
Finnishneptunium
FriulianNetuni
Irishneiptiúiniam
GalicianNeptunio
ManxNepçhunium
Hakka Chineseneptunium
Hebrewנפטוניום
Fiji HindiNeptunium
Croatianneptunij
Haitian CreoleNeptinyòm
Hungarianneptúnium
Armenianնեպտունիում
Interlinguaneptunium
Indonesianneptunium
Idoneptunio
Japaneseネプツニウム
Lojbanjinmrneptuni
JavaneseNeptunium
Kannadaನೆಪ್ಚೂನಿಯಮ್
Korean넵투늄
KomiНептуний
Latinneptunium
LuxembourgishNeptunium
LigurianNettunnio
Lithuanianneptūnis
Latvianneptūnijs
Malayalamനെപ്റ്റ്യൂണിയം
Marathiनेप्चूनियम
Western MariНептуний
MalayNeptunium
Burmeseနပ်ကျူနီယမ်
nahTlāloctepoztli
Low GermanNeptunium
Polishneptun
pnbنیپچونیم
Portugueseneptúnio
QuechuaNeptunyu
Romanianneptuniu
Russianнептуний
SakhaНептуниум
Siciliannittuniu
Serbo-CroatianNeptunijum
Slovakneptúnium
Slovenianneptunij
Serbianнептунијум
Saterland FrisianNeptunium
Swahilineptuni
Thaiเนปทูเนียม
Turkishneptünyum
Uyghurنېپتونىي
Ukrainianнептуній
Urduنیپچونیئم
VepsNeptunii
Vietnameseneptuni
WarayNeptunyo
KalmykНептуниүм
YorubaNẹ́ptúníọ̀m
Chinese錼
Georgianნეპტუნიუმი
Icelandicneptúnín
CebuanoNeptunyo
Macedonianнептуниум
Central Kurdishنێپتوونیۆم
BretonNeptuniom
KazakhНептуний
Gujaratiનેપ્ચ્યુનીયમ
Odiaନେପ୍‌ଚୁନିଅମ
Tamilநெப்டூனியம்
Occitanneptuni
PiedmonteseNetuni
TatarНептуний
Hindiनेप्टूनियम
Newariनेप्टुनियम
Belarusian (Taraskievica orthography)Нэптун
Cantonese錼
AlbanianNeptuni (element kimik)
UzbekNeptuniy
Chinese (China)镎
Chinese (Simplified)镎
Chinese (Taiwan)錼
Chinese (Hong Kong SAR China)錼
Chinese (Traditional)錼
AromanianNeptuniu
KyrgyzНептуний
Nepaliनेप्ट्युनियम
LimburgishNeptunium
FaroeseNeptunium
Sanskritनेप्टुनियम
Maltesenettunju
Scottish GaelicNeiptiunium
Teluguనెప్ట్యూనియం
cdoNeptunium
Min Nan ChineseNeptunium
AsturianNeptuniu
Paliनेप्टुनियम
Bhojpuriनेप्चुनियम
Tibetanནེབ་ཊུ་ནིམ།
Chinese (Macao SAR China)錼
Chinese (Malaysia)镎
Chinese (Singapore)镎
Portuguese (Brazil)netúnio
Literary Chinese錼
TagalogNeptunyo
kbpNɛptʊnɩyɔm
AfrikaansNeptunium
Lingua Franca Novanetunio
Northern FrisianNeptuunium
oloNeptunii
Volapükneptunin
Mongolianнептуни
TajikНептуний
Wu Chinese镎
SardinianNetùniu
BashkirНептуний
Moroccan Arabicنيپتونيوم
Egyptian Arabicنبتونيوم
Pashtoنېپټونيوم
CornishNeptuniom
BalineseNéptunium

Neptunium on ChemicalAid

Australian Educational Vocabulary ID	scot/3547
CAB ID	7537
CAS Registry Number	7439-99-8
ChEBI ID	33387
ChemSpider ID	22375
DSSTOX compound identifier	DTXCID3047639
DSSTox substance ID	DTXSID5074840
Den Store Danske ID	neptunium
ECHA Substance Infocard ID	100.028.280
Elhuyar ZTH ID	028601
Encyclopædia Britannica Online ID	science/neptunium
Encyclopædia Universalis ID	neptunium
Freebase ID	/m/025s4ry
French Vikidia ID	Neptunium
GND ID	4171471-4
Great Russian Encyclopedia Online ID	2262013
InChI	InChI=1S/Np
InChIKey	LFNLGNPSGWYGGD-UHFFFAOYSA-N
KBpedia ID	Neptunium
Library of Congress authority ID	sh85090879
MeSH descriptor ID	D009405
Namuwiki ID	넵투늄
National Library of Israel J9U ID	987007565628105171
OmegaWiki Defined Meaning	377199
OpenAlex ID	C516372188
PubChem CID	23933
Quora topic ID	Neptunium
Römpp online ID	RD-14-00817
Store norske leksikon ID	neptunium
Treccani ID	nettunio
UNII	6200K977BQ
USGS Thesaurus ID	1518
WordNet 3.1 Synset ID	14670581-n
YSO ID	12863

Neptunium (Np)

Properties

Isotopes of Neptunium

219Np

220Np

221Np

222Np

223Np

224Np

225Np

226Np

227Np

228Np

229Np

230Np

231Np

232Np

233Np

234Np

235Np

236Np

237Np

238Np

239Np

240Np

241Np

242Np

243Np

244Np

245Np