Neptunyum (Np)

chemical element with the atomic number of 93 and symbol Np

Atomic Number	93
Atomic Weight	237
mass number	219

Group
Period	7
Block	f

proton	93 p⁺
neutron	126 n⁰
electron	93 e^-

Physical Property

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
dosedh	20.2 g/cm³

Chemical Property

nerth

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

enthalpy of vaporization	336 kJ/mol
enthalpy of fusion	9.6 kJ/mol
standard enthalpy of formation	464.8 kJ/mol
electron

electron shell	2, 8, 18, 32, 22, 9, 2

valence electron	2 ⓘ

aray an elektrons	[Rn] 5f⁴ 6d¹ 7s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 5f⁴ 6d¹ 7s²

oxidation number	2, 3, 4, 5, 6, 7
electronegativity	0.14265 1.3
Electrophilicity Index
fundamental state of matter

phase of matter	Solid
gaseous state of matter
Boiling Point
Melting Point	917.15 K
critical pressure
critical temperature
triple point
appearance
liw	Silver #ffffff #0080ff #0080ff
appearance	silvery metallic
refractive index
thermodynamic material property
Thermal Conductivity
thermal expansion
molar heat capacity
Specific Heat Capacity
heat capacity ratio
electrical properties
type	Conductor
electrical conductivity	0.83 MS/m
electrical resistivity	0.0000012 Ω*m
superconductivity
magnetism
type
magnetic susceptibility (Mass)
magnetic susceptibility (Molar)
magnetic susceptibility (Volume)
magnetic ordering
Curie temperature
Néel temperature
kesweyth
Crystal Structure	Simple Orthorhombic (ORC)
lattice constant	4.72 Å
Lattice Angles	π/2, π/2, π/2
mechanical property
hardness
bulk modulus
shear modulus
Young's modulus
Poisson's ratio
speed of sound
classification
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	37
Mendeleev Number	22
Pettifor Number	44
Geochemical Class
Goldschmidt classification	synthetic

other

Gas Basicity
polarizability	151 ± 20 a₀
C6 Dispersion Coefficient
allotrope
Neutron cross section	180
Neutron Mass Absorption
quantum number	6L11/2
space group	62 (Pnma)

Isotopes of Neptunium

Stable Isotopes	0
Unstable Isotopes	27
Natural Isotopes	0

²¹⁹Np

mass number	219
neutron number	126
relative atomic mass	219.031601865 ± 0.000098732 Da
g-factor
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	570 ± 450 us
spin	9/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	29 ± 11 ns
spin	1
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life
spin	9/2
nuclear quadrupole moment
dydhyas diskudhans
parity	-

decay mode	intensity
α (α emission)

²²²Np

mass number	222
neutron number	129
relative atomic mass	222.033574706 ± 0.000040849 Da
g-factor
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	480 ± 190 ns
spin	1
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.5 ± 0.8 us
spin	9/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	48 ± 19 us
spin	2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	6.5 ± 3.5 ms
spin	9/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	35 ± 10 ms
spin
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	510 ± 60 ms
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	61.4 ± 1.4 s
spin	4
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	4 ± 0.18 m
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	4.6 ± 0.3 m
spin	4
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	48.8 ± 0.2 m
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	14.7 ± 0.3 m
spin	5
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	36.2 ± 0.1 m
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	4.4 ± 0.1 d
spin	0
nuclear quadrupole moment	0
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	396.1 ± 1.2 d
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	153 ± 5 ky
spin	6
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.144 ± 0.007 My
spin	5/2
nuclear quadrupole moment	3.886 ± 0.006
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.099 ± 0.002 d
spin	2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.356 ± 0.003 d
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	61.9 ± 0.2 m
spin	5
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	13.9 ± 0.2 m
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.2 ± 0.2 m
spin	1
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	1.85 ± 0.15 m
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life	2.29 ± 0.16 m
spin	7
nuclear quadrupole moment
dydhyas diskudhans	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
natural abundance
radioactivity	☢️ elven radyoweythresek
half-life
spin	5/2
nuclear quadrupole moment
dydhyas diskudhans
parity	+

decay mode	intensity
β⁻ (β⁻ decay)

istori

diskudher po dismyger	E.M. McMillan, P.H. Abelson
location of discovery	United States
dydhyas diskudhans	1940
Etymologyl	Named for the planet Neptune.
pronunciation	nep-TOO-ni-em (en)

source

Abundance
Abundance in Earth's crust
natural abundance (Keynvor)
natural abundance (Korf)	0 %
natural abundance (meteoroid)	0 %
natural abundance (Howl)	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Neptunyum 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
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
honanieth GND	4171471-4

Neptunyum (Np)

Physical Property

Chemical Property

other

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

istori

source

Nuclear Screening Constants

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