Isotopes of Neptunium

List of known isotopes of the element Neptunium.

Isotope	t½	%	Spin/parity	Radius	Isotopic mass	Discovery
²¹⁹Np	0.15 ± ms	syn.	(9/2-)	—	2.19·10⁸ ±98.73 keV/c²	2015
²²⁰Np	25 ± us	syn.	—	—	2.2·10⁸ ±32.97 keV/c²	2019
²²²Np	0.38 ± us	syn.	—	—	2.22·10⁸ ±40.84 keV/c²	2020
²²³Np	2.2 ± us	syn.	(9/2-)	—	2.23·10⁸ ±88.95 keV/c²	2017
²²⁴Np	38 ± us	syn.	—	—	2.24·10⁸ ±31.05 keV/c²	2018
²²⁵Np	3.6 ± ms	syn.	—	—	2.25·10⁸ ±98.35 keV/c²	1994
²²⁶Np	35 ±10 ms	syn.	—	—	2.26·10⁸ ±109.5 keV/c²	1990
²²⁷Np	0.51 ±6 s	syn.	—	—	2.27·10⁸ ±82.65 keV/c²	1990
²²⁸Np	61.4 ±14 s	syn.	—	—	2.28·10⁸ ±108 keV/c²	1994
²²⁹Np	4 ±2 m	syn.	—	—	2.29·10⁸ ±108.6 keV/c²	1968
²³⁰Np	4.6 ±3 m	syn.	—	—	2.3·10⁸ ±59.05 keV/c²	1968
²³¹Np	48.8 ±2 m	syn.	(5/2-)	—	2.31·10⁸ ±54.91 keV/c²	1950
²³²Np	14.7 ±3 m	syn.	(4+)	—	2.32·10⁸ ±107 keV/c²	1950
²³³Np	36.2 ±1 m	syn.	(5/2+)	—	2.33·10⁸ ±54.72 keV/c²	1950
²³⁴Np	4.4 ±1 d	syn.	(0+)	—	2.34·10⁸ ±9.014 keV/c²	1949
²³⁵Np	396.1 ±12 d	syn.	5/2+	—	2.35·10⁸ ±1.49 keV/c²	1949
²³⁶Np	155,000 ±1 a	syn.	6(-)	—	2.36·10⁸ ±54.12 keV/c²	1949
²³⁷Np	2.144·10⁶ ±7 a	syn.	5/2+	—	2.37·10⁸ ±1.201 keV/c²	1948
²³⁸Np	2.099 ±2 d	syn.	2+	—	2.38·10⁸ ±1.22 keV/c²	1949
²³⁹Np	2.356 ±3 d	syn.	5/2+	—	2.39·10⁸ ±1.406 keV/c²	1940
²⁴⁰Np	61.9 ±2 m	syn.	(5+)	—	2.4·10⁸ ±18.28 keV/c²	1953
²⁴¹Np	13.9 ±2 m	syn.	5/2+	—	2.41·10⁸ ±107.3 keV/c²	1959
²⁴²Np	2.2 ±2 m	syn.	(1+)	—	2.42·10⁸ ±214.7 keV/c²	1979
²⁴³Np	1.85 ±15 m	syn.	(5/2)	—	2.43·10⁸ ±34 keV/c²	1979
²⁴⁴Np	2.29 ±16 m	syn.	(7-)	—	2.44·10⁸ ±107 keV/c²	1987

219NpNeptunium-219

Classification	z: 93; n: 126; m: 219
Half life	0.15 ± ms
Natural abundance	synthetic nuclide
Spin/parity	(9/2-)
Decay modes	α decay; proton emission
Discovery	2015
Mass excess	29,430 ±91.96 keV
Binding energy	7,604 ±0.4199 keV
Single-particle energy	-253.4 ±92.98 keV
Q value for electron capture	6,140 ±92.93 keV

Point at nuclide Decay chain of Neptunium-219

220NpNeptunium-220

Classification	z: 93; n: 127; m: 220
Half life	25 ± us
Natural abundance	synthetic nuclide
Decay modes	α decay
Discovery	2019
Mass excess	30,470 ±30.71 keV
Binding energy	7,602 ±0.1396 keV
Single-particle energy	109.9 ±33.48 keV
Neutron separation energy	7,033 ±96.96 keV

Point at nuclide Decay chain of Neptunium-220

222NpNeptunium-222

Classification	z: 93; n: 129; m: 222
Half life	0.38 ± us
Natural abundance	synthetic nuclide
Decay modes	α decay
Discovery	2020
Mass excess	31,270 ±38.05 keV
Binding energy	7,602 ±0.1714 keV
Single-particle energy	534.3 ±81.55 keV
Neutron separation energy	6,707 ±204 keV
β⁻ decay energy	-3,785 ±302 keV
β⁻ decay energy with neutron	-12,730 ±302 keV

Point at nuclide Decay chain of Neptunium-222

223NpNeptunium-223

Classification	z: 93; n: 130; m: 223
Half life	2.2 ± us
Natural abundance	synthetic nuclide
Spin/parity	(9/2-)
Decay modes	α decay
Discovery	2017
Mass excess	30,650 ±82.86 keV
Binding energy	7,607 ±0.3716 keV
Single-particle energy	903.2 ±97.82 keV
Neutron separation energy	8,687 ±91.17 keV
Q value for electron capture	4,613 ±101.7 keV
β⁻ decay energy	-5,462 ±311 keV
β⁻ decay energy with neutron	-12,480 ±311 keV

Point at nuclide Decay chain of Neptunium-223

224NpNeptunium-224

Classification	z: 93; n: 131; m: 224
Half life	38 ± us
Natural abundance	synthetic nuclide
Decay modes	α decay
Discovery	2018
Mass excess	32,030 ±28.92 keV
Binding energy	7,603 ±0.1291 keV
Single-particle energy	1,302 ±65.75 keV
Neutron separation energy	6,697 ±87.76 keV
Q value for electron capture	6,289 ±32.7 keV
β⁻ decay energy	-3,248 ±301 keV
β⁻ decay energy with neutron	-12,160 ±301 keV

Point at nuclide Decay chain of Neptunium-224

225NpNeptunium-225

Classification	z: 93; n: 132; m: 225
Half life	3.6 ± ms
Natural abundance	synthetic nuclide
Decay modes	α decay; electron capture + β⁺ decay
Discovery	1994
Mass excess	31,610 ±91.61 keV
Binding energy	7,607 ±0.4072 keV
Single-particle energy	1,413 ±92.87 keV
Neutron separation energy	8,485 ±96.07 keV
Q value for electron capture	4,246 ±92.15 keV
β⁻ decay energy	-4,682 ±314 keV
β⁻ decay energy with neutron	-11,740 ±314 keV

Point at nuclide Decay chain of Neptunium-225

226NpNeptunium-226

Classification	z: 93; n: 133; m: 226
Half life	35 ±10 ms
Natural abundance	synthetic nuclide
Decay modes	α decay
Discovery	1990
Mass excess	32,810 ±102 keV
Binding energy	7,604 ±0.4516 keV
Single-particle energy	1,844 ±102.5 keV
Neutron separation energy	6,872 ±137.1 keV
Q value for electron capture	5,488 ±102.6 keV
β⁻ decay energy	-2,813 ±225 keV
β⁻ decay energy with neutron	-11,560 ±317 keV

Point at nuclide Decay chain of Neptunium-226

227NpNeptunium-227

Classification	z: 93; n: 134; m: 227
Half life	0.51 ±6 s
Natural abundance	synthetic nuclide
Decay modes	α decay
Discovery	1990
Mass excess	32,570 ±76.98 keV
Binding energy	7,607 ±0.3392 keV
Single-particle energy	2,038 ±77.76 keV
Neutron separation energy	8,309 ±127.8 keV
Q value for electron capture	3,533 ±77.45 keV
β⁻ decay energy	-4,191 ±126 keV
β⁻ decay energy with neutron	-11,130 ±215 keV

Point at nuclide Decay chain of Neptunium-227

228NpNeptunium-228

Classification	z: 93; n: 135; m: 228
Half life	61.4 ±14 s
Natural abundance	synthetic nuclide
Decay modes	electron capture (EC); α decay
Discovery	1994
Mass excess	33,820 ±100 keV
Binding energy	7,604 keV
Single-particle energy	2,509 ±101 keV
Neutron separation energy	6,825 ±126 keV
Q value for electron capture	4,604 ±100.9 keV
β⁻ decay energy	-2,283 ±103 keV
β⁻ decay energy with neutron	-11,020 ±141 keV

Point at nuclide Decay chain of Neptunium-228

229NpNeptunium-229

Classification	z: 93; n: 136; m: 229
Half life	4 ±2 m
Natural abundance	synthetic nuclide
Decay modes	α decay; electron capture (EC)
Discovery	1968
Mass excess	33,800 ±101.1 keV
Binding energy	7,605 ±0.4418 keV
Single-particle energy	2,707 ±102 keV
Neutron separation energy	8,095 ±142 keV
Q value for electron capture	2,590 ±101.3 keV
β⁻ decay energy	-3,594 ±117.9 keV
β⁻ decay energy with neutron	-10,380 ±103.8 keV

Point at nuclide Decay chain of Neptunium-229

230NpNeptunium-230

Classification	z: 93; n: 137; m: 230
Half life	4.6 ±3 m
Natural abundance	synthetic nuclide
Decay modes	electron capture + β⁺ decay; α decay
Discovery	1968
Mass excess	35,230 ±55 keV
Binding energy	7,601 ±0.2392 keV
Single-particle energy	3,262 ±55.29 keV
Neutron separation energy	6,636 ±115.1 keV
Q value for electron capture	3,621 ±55.19 keV
β⁻ decay energy	-1,696 ±56.85 keV
β⁻ decay energy with neutron	-10,230 ±81.85 keV

Point at nuclide Decay chain of Neptunium-230

231NpNeptunium-231

Classification	z: 93; n: 138; m: 231
Half life	48.8 ±2 m
Natural abundance	synthetic nuclide
Spin/parity	(5/2-)
Decay modes	electron capture + β⁺ decay; α decay
Discovery	1950
Mass excess	35,620 ±51.15 keV
Binding energy	7,602 ±0.2214 keV
Single-particle energy	3,280 ±51.33 keV
Neutron separation energy	7,684 ±75.1 keV
Q value for electron capture	1,817 ±51.22 keV
β⁻ decay energy	-2,685 ±55.69 keV
β⁻ decay energy with neutron	-9,380 ±53.14 keV

Point at nuclide Decay chain of Neptunium-231

232NpNeptunium-232

Classification	z: 93; n: 139; m: 232
Half life	14.7 ±3 m
Natural abundance	synthetic nuclide
Spin/parity	(4+)
Decay modes	electron capture + β⁺ decay; α decay
Discovery	1950
Mass excess	37,350 ±100 keV
Binding energy	7,597 keV
Single-particle energy	3,735 ±100 keV
Neutron separation energy	6,336 ±112 keV
Q value for electron capture	2,749 ±100 keV
β⁻ decay energy	-1,001 ±101 keV
β⁻ decay energy with neutron	-9,020 ±102 keV

Point at nuclide Decay chain of Neptunium-232

233NpNeptunium-233

Classification	z: 93; n: 140; m: 233
Half life	36.2 ±1 m
Natural abundance	synthetic nuclide
Spin/parity	(5/2+)
Decay modes	electron capture (EC); α decay
Discovery	1950
Mass excess	37,940 ±50.98 keV
Binding energy	7,596 ±0.2188 keV
Single-particle energy	3,949 ±50.98 keV
Neutron separation energy	7,482 ±112 keV
Q value for electron capture	1,029 ±51.03 keV
β⁻ decay energy	-2,104 ±74.38 keV
β⁻ decay energy with neutron	-8,484 ±53.69 keV

Point at nuclide Decay chain of Neptunium-233

234NpNeptunium-234

Classification	z: 93; n: 141; m: 234
Half life	4.4 ±1 d
Natural abundance	synthetic nuclide
Spin/parity	(0+)
Decay modes	electron capture + β⁺ decay
Discovery	1949
Mass excess	39,950 ±8.397 keV
Binding energy	7,589 ±0.0359 keV
Single-particle energy	4,253 ±8.557 keV
Neutron separation energy	6,065 ±51.64 keV
Q value for electron capture	1,809 ±8.473 keV
β⁻ decay energy	-395.2 ±10.75 keV
β⁻ decay energy with neutron	-8,169 ±54.82 keV

Point at nuclide Decay chain of Neptunium-234

235NpNeptunium-235

Classification	z: 93; n: 142; m: 235
Half life	396.1 ±12 d
Natural abundance	synthetic nuclide
Spin/parity	5/2+
Decay modes	electron capture (EC); α decay
Discovery	1949
Mass excess	41,040 ±1.388 keV
Binding energy	7,587 ±0.0059 keV
Single-particle energy	4,390 ±0.8804 keV
Neutron separation energy	6,983 ±8.367 keV
Q value for electron capture	124.2 ±1.781 keV
β⁻ decay energy	-1,140 ±20.49 keV
β⁻ decay energy with neutron	-7,379 ±6.857 keV

Point at nuclide Decay chain of Neptunium-235

236NpNeptunium-236

Classification	z: 93; n: 143; m: 236
Half life	155,000 ±1 a
Natural abundance	synthetic nuclide
Spin/parity	6(-)
Decay modes	electron capture (EC); β⁻ decay; α decay
Discovery	1949
Mass excess	43,370 ±50.42 keV
Binding energy	7,579 ±0.2136 keV
Single-particle energy	4,829 ±50.41 keV
Neutron separation energy	5,736 ±50.41 keV
Q value for electron capture	933.5 ±50.43 keV
β⁻ decay energy	476.5 ±50.38 keV
β⁻ decay energy with neutron	-6,876 ±54.41 keV

Point at nuclide Decay chain of Neptunium-236

237NpNeptunium-237

Classification	z: 93; n: 144; m: 237
Half life	2.144·10⁶ ±7 a
Natural abundance	synthetic nuclide
Spin/parity	5/2+
Decay modes	α decay; spontaneous fission
Discovery	1948
Mass excess	44,870 ±1.12 keV
Binding energy	7,574 ±0.0047 keV
Single-particle energy	4,861 ±0.2517 keV
Neutron separation energy	6,577 ±50.41 keV
Q value for electron capture	-518.6 ±1.643 keV
β⁻ decay energy	-220.1 ±1.294 keV
β⁻ decay energy with neutron	-6,102 ±1.64 keV
Magnetic dipole moment	3.16 ±0.1 μN
Electric quadrupole moment	3.886 ±0.006 b

Point at nuclide Decay chain of Neptunium-237

238NpNeptunium-238

Classification	z: 93; n: 145; m: 238
Half life	2.099 ±2 d
Natural abundance	synthetic nuclide
Spin/parity	2+
Decay modes	β⁻ decay
Discovery	1949
Mass excess	47,450 ±1.137 keV
Binding energy	7,566 ±0.0048 keV
Single-particle energy	5,224 ±0.5572 keV
Neutron separation energy	5,488 ±0.2 keV
Q value for electron capture	146.8 ±1.876 keV
β⁻ decay energy	1,291 ±0.4573 keV
β⁻ decay energy with neutron	-5,709 ±1.309 keV

Point at nuclide Decay chain of Neptunium-238

239NpNeptunium-239

Classification	z: 93; n: 146; m: 239
Half life	2.356 ±3 d
Natural abundance	synthetic nuclide
Spin/parity	5/2+
Decay modes	β⁻ decay
Discovery	1940
Mass excess	49,310 ±1.31 keV
Binding energy	7,560 ±0.0055 keV
Single-particle energy	5,285 ±1.483 keV
Neutron separation energy	6,214 ±0.9939 keV
Q value for electron capture	-1,262 ±1.993 keV
β⁻ decay energy	722.7 ±0.9304 keV
β⁻ decay energy with neutron	-4,924 ±0.977 keV
Magnetic dipole moment	2.2 ±0.4 μN

Point at nuclide Decay chain of Neptunium-239

240NpNeptunium-240

Classification	z: 93; n: 147; m: 240
Half life	61.9 ±2 m
Natural abundance	synthetic nuclide
Spin/parity	(5+)
Decay modes	β⁻ decay
Discovery	1953
Mass excess	52,310 ±17.03 keV
Binding energy	7,550 ±0.071 keV
Single-particle energy	5,545 ±17.05 keV
Neutron separation energy	5,066 ±17.03 keV
Q value for electron capture	-399.3 ±17.22 keV
β⁻ decay energy	2,190 ±17.01 keV
β⁻ decay energy with neutron	-4,344 ±17.01 keV

Point at nuclide Decay chain of Neptunium-240

241NpNeptunium-241

Classification	z: 93; n: 148; m: 241
Half life	13.9 ±2 m
Natural abundance	synthetic nuclide
Spin/parity	5/2+
Decay modes	β⁻ decay
Discovery	1959
Mass excess	54,310 ±100 keV
Binding energy	7,544 ±0.415 keV
Single-particle energy	5,689 ±100 keV
Neutron separation energy	6,072 ±101.4 keV
Q value for electron capture	-1,882 ±220 keV
β⁻ decay energy	1,360 ±100 keV
β⁻ decay energy with neutron	-3,882 ±100 keV

Point at nuclide Decay chain of Neptunium-241

242NpNeptunium-242

Classification	z: 93; n: 149; m: 242
Half life	2.2 ±2 m
Natural abundance	synthetic nuclide
Spin/parity	(1+)
Decay modes	β⁻ decay
Discovery	1979
Mass excess	57,410 ±200 keV
Binding energy	7,533 ±0.8265 keV
Single-particle energy	6,069 ±280 keV
Neutron separation energy	4,969 ±223.6 keV
Q value for electron capture	-1,204 ±283.5 keV
β⁻ decay energy	2,700 ±200 keV
β⁻ decay energy with neutron	-3,610 ±200 keV

Point at nuclide Decay chain of Neptunium-242

243NpNeptunium-243

Classification	z: 93; n: 150; m: 243
Half life	1.85 ±15 m
Natural abundance	synthetic nuclide
Spin/parity	(5/2)
Decay modes	β⁻ decay
Discovery	1979
Mass excess	59,800 ±32 keV
Binding energy	7,526 keV
Single-particle energy	6,103 ±203 keV
Neutron separation energy	5,682 ±203 keV
Q value for electron capture	-2,674 ±301.7 keV
β⁻ decay energy	2,051 ±32 keV
β⁻ decay energy with neutron	-2,982 ±32 keV

Point at nuclide Decay chain of Neptunium-243

244NpNeptunium-244

Classification	z: 93; n: 151; m: 244
Half life	2.29 ±16 m
Natural abundance	synthetic nuclide
Spin/parity	(7-)
Decay modes	β⁻ decay
Discovery	1987
Mass excess	63,240 ±100 keV
Binding energy	7,514 keV
Single-particle energy	6,529 ±316 keV
Neutron separation energy	4,637 ±105 keV
β⁻ decay energy	3,434 ±100 keV
β⁻ decay energy with neutron	-2,586 ±100 keV

Point at nuclide Decay chain of Neptunium-244

Isotopes of Neptunium

219NpNeptunium-219ads_clickcall_splitdownload

220NpNeptunium-220ads_clickcall_splitdownload

222NpNeptunium-222ads_clickcall_splitdownload

223NpNeptunium-223ads_clickcall_splitdownload

224NpNeptunium-224ads_clickcall_splitdownload

225NpNeptunium-225ads_clickcall_splitdownload

226NpNeptunium-226ads_clickcall_splitdownload

227NpNeptunium-227ads_clickcall_splitdownload

228NpNeptunium-228ads_clickcall_splitdownload

229NpNeptunium-229ads_clickcall_splitdownload

230NpNeptunium-230ads_clickcall_splitdownload

231NpNeptunium-231ads_clickcall_splitdownload

232NpNeptunium-232ads_clickcall_splitdownload

233NpNeptunium-233ads_clickcall_splitdownload

234NpNeptunium-234ads_clickcall_splitdownload

235NpNeptunium-235ads_clickcall_splitdownload

236NpNeptunium-236ads_clickcall_splitdownload

237NpNeptunium-237ads_clickcall_splitdownload

238NpNeptunium-238ads_clickcall_splitdownload

239NpNeptunium-239ads_clickcall_splitdownload

240NpNeptunium-240ads_clickcall_splitdownload

241NpNeptunium-241ads_clickcall_splitdownload

242NpNeptunium-242ads_clickcall_splitdownload

243NpNeptunium-243ads_clickcall_splitdownload

244NpNeptunium-244ads_clickcall_splitdownload

219NpNeptunium-219

220NpNeptunium-220

222NpNeptunium-222

223NpNeptunium-223

224NpNeptunium-224

225NpNeptunium-225

226NpNeptunium-226

227NpNeptunium-227

228NpNeptunium-228

229NpNeptunium-229

230NpNeptunium-230

231NpNeptunium-231

232NpNeptunium-232

233NpNeptunium-233

234NpNeptunium-234

235NpNeptunium-235

236NpNeptunium-236

237NpNeptunium-237

238NpNeptunium-238

239NpNeptunium-239

240NpNeptunium-240

241NpNeptunium-241

242NpNeptunium-242

243NpNeptunium-243

244NpNeptunium-244