HomeTable of NuclidesCuriumIsotopes

Isotopes of Curium

List of known isotopes of the element Curium.

Isotope	t½	%	Spin/parity	Radius	Isotopic mass	Discovery
²³³Cm	23 ± s	syn.	—	—	2.33·10⁸ ±87.05 keV/c²	2001
²³⁴Cm	51 ±12 s	syn.	0+	—	2.34·10⁸ ±18.33 keV/c²	2001
²³⁵Cm	stab.	syn.	—	—	2.35·10⁸ ±110 keV/c²	1981
²³⁶Cm	6.8 ±8 m	syn.	0+	—	2.36·10⁸ ±18.93 keV/c²	2010
²³⁷Cm	stab.	syn.	—	—	2.37·10⁸ ±79.87 keV/c²	2002
²³⁸Cm	2.2 ±4 h	syn.	0+	—	2.38·10⁸ ±13.13 keV/c²	1994
²³⁹Cm	2.7 ±8 h	syn.	(7/2-)	—	2.39·10⁸ ±161.1 keV/c²	1952
²⁴⁰Cm	27 ±1 d	syn.	0+	—	2.4·10⁸ ±2.045 keV/c²	1949
²⁴¹Cm	32.8 ±2 d	syn.	1/2+	—	2.41·10⁸ ±1.725 keV/c²	1952
²⁴²Cm	162.8 ±8 d	syn.	0+	5.828 ±0.0192 fm	2.42·10⁸ ±1.224 keV/c²	1949
²⁴³Cm	29.1 ±1 a	syn.	5/2+	—	2.43·10⁸ ±1.605 keV/c²	1950
²⁴⁴Cm	18.11 ±3 a	syn.	0+	5.842 ±0.0181 fm	2.44·10⁸ ±1.187 keV/c²	1950
²⁴⁵Cm	8,423 ±74 a	syn.	7/2+	5.847 ±0.0182 fm	2.45·10⁸ ±1.233 keV/c²	1954
²⁴⁶Cm	4,706 ±40 a	syn.	0+	5.856 ±0.0184 fm	2.46·10⁸ ±1.637 keV/c²	1954
²⁴⁷Cm	1.56·10⁷ ±5 a	syn.	9/2-	—	2.47·10⁸ ±4.076 keV/c²	1954
²⁴⁸Cm	348,000 ±6 a	syn.	0+	5.868 ±0.0193 fm	2.48·10⁸ ±2.531 keV/c²	1956
²⁴⁹Cm	64.15 ±3 m	syn.	1/2+	—	2.49·10⁸ ±2.545 keV/c²	1956
²⁵⁰Cm	8,300 a	syn.	0+	—	2.5·10⁸ ±11.02 keV/c²	1966
²⁵¹Cm	16.8 ±2 m	syn.	(1/2+)	—	2.51·10⁸ ±24.36 keV/c²	1978

233CmCurium-233

Classification	z: 96; n: 137; m: 233
Half life	23 ± s
Natural abundance	synthetic nuclide
Decay modes	electron capture + β⁺ decay; α decay
Discovery	2001
Mass excess	47,290 ±81.09 keV
Binding energy	7,546 ±0.348 keV
Single-particle energy	3,415 ±311 keV
Neutron separation energy	7,111 ±217 keV
Q value for electron capture	4,008 ±139.9 keV
β⁻ decay energy	-5,478 ±247 keV

Point at nuclide Decay chain of Curium-233

234CmCurium-234

Classification	z: 96; n: 138; m: 234
Half life	51 ±12 s
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; spontaneous fission; electron capture + β⁺ decay
Discovery	2001
Mass excess	46,720 ±17.07 keV
Binding energy	7,550 ±0.073 keV
Single-particle energy	3,851 ±115 keV
Neutron separation energy	8,642 ±82.85 keV
Q value for electron capture	2,260 ±160.9 keV
β⁻ decay energy	-6,673 ±154 keV
β⁻ decay energy with neutron	-14,120 ±233 keV

Point at nuclide Decay chain of Curium-234

235CmCurium-235

Classification	z: 96; n: 139; m: 235
Half life	stable nuclide
Natural abundance	synthetic nuclide
Discovery	1981
Mass excess	48,010 ±102 keV
Binding energy	7,547 keV
Single-particle energy	3,737 ±190 keV
Neutron separation energy	6,780 ±104 keV
Q value for electron capture	3,388 ±114.8 keV
β⁻ decay energy	-4,757 ±413 keV
β⁻ decay energy with neutron	-13,460 ±184 keV

Point at nuclide

236CmCurium-236

Classification	z: 96; n: 140; m: 236
Half life	6.8 ±8 m
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	electron capture (EC); α decay
Discovery	2010
Mass excess	47,850 ±17.63 keV
Binding energy	7,550 ±0.0747 keV
Single-particle energy	4,060 ±55.63 keV
Neutron separation energy	8,232 ±104 keV
Q value for electron capture	1,811 ±120.3 keV
β⁻ decay energy	-5,689 ±361 keV
β⁻ decay energy with neutron	-12,990 ±401 keV

Point at nuclide Decay chain of Curium-236

237CmCurium-237

Classification	z: 96; n: 141; m: 237
Half life	stable nuclide
Natural abundance	synthetic nuclide
Discovery	2002
Mass excess	49,240 ±74.39 keV
Binding energy	7,546 ±0.3139 keV
Single-particle energy	4,082 ±140 keV
Neutron separation energy	6,676 ±76.44 keV
Q value for electron capture	2,677 ±94.95 keV
β⁻ decay energy	-3,963 ±242 keV
β⁻ decay energy with neutron	-12,370 ±368 keV

Point at nuclide

238CmCurium-238

Classification	z: 96; n: 142; m: 238
Half life	2.2 ±4 h
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	electron capture (EC); α decay; spontaneous fission
Discovery	1994
Mass excess	49,440 ±12.23 keV
Binding energy	7,547 ±0.0514 keV
Single-particle energy	4,413 ±61 keV
Neutron separation energy	7,873 ±75.38 keV
Q value for electron capture	1,023 ±60.16 keV
β⁻ decay energy	-4,771 ±256 keV
β⁻ decay energy with neutron	-11,840 ±231 keV

Point at nuclide Decay chain of Curium-238

239CmCurium-239

Classification	z: 96; n: 143; m: 239
Half life	2.7 ±8 h
Natural abundance	synthetic nuclide
Spin/parity	(7/2-)
Decay modes	electron capture (EC); α decay
Discovery	1952
Mass excess	51,140 ±150 keV
Binding energy	7,543 ±0.6279 keV
Single-particle energy	4,563 ±161.2 keV
Neutron separation energy	6,369 ±150.5 keV
Q value for electron capture	1,756 ±150 keV
β⁻ decay energy	-3,103 ±256 keV
β⁻ decay energy with neutron	-11,150 ±297 keV

Point at nuclide Decay chain of Curium-239

240CmCurium-240

Classification	z: 96; n: 144; m: 240
Half life	27 ±1 d
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; electron capture (EC); spontaneous fission
Discovery	1949
Mass excess	51,720 ±1.905 keV
Binding energy	7,542 ±0.0079 keV
Single-particle energy	4,955 ±2.338 keV
Neutron separation energy	7,494 ±150 keV
Q value for electron capture	214.1 ±13.96 keV
β⁻ decay energy	-3,940 ±150 keV
β⁻ decay energy with neutron	-10,600 ±207 keV

Point at nuclide Decay chain of Curium-240

241CmCurium-241

Classification	z: 96; n: 145; m: 241
Half life	32.8 ±2 d
Natural abundance	synthetic nuclide
Spin/parity	1/2+
Decay modes	electron capture (EC); α decay
Discovery	1952
Mass excess	53,700 ±1.607 keV
Binding energy	7,536 ±0.0067 keV
Single-particle energy	5,097 ±13.83 keV
Neutron separation energy	6,093 ±2.09 keV
Q value for electron capture	767.4 ±1.955 keV
β⁻ decay energy	-2,279 ±165 keV
β⁻ decay energy with neutron	-10,040 ±150 keV

Point at nuclide Decay chain of Curium-241

242CmCurium-242

Classification	z: 96; n: 146; m: 242
Half life	162.8 ±8 d
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; spontaneous fission; other decay
Discovery	1949
Mass excess	54,800 ±1.141 keV
Binding energy	7,534 ±0.0047 keV
Single-particle energy	5,419 ±0.402 keV
Neutron separation energy	6,969 ±1.233 keV
Q value for electron capture	-664.4 ±1.597 keV
β⁻ decay energy	-2,948 ±135 keV
β⁻ decay energy with neutron	-9,248 ±165 keV

Point at nuclide Decay chain of Curium-242

243CmCurium-243

Classification	z: 96; n: 147; m: 243
Half life	29.1 ±1 a
Natural abundance	synthetic nuclide
Spin/parity	5/2+
Decay modes	α decay; electron capture (EC); spontaneous fission
Discovery	1950
Mass excess	57,180 ±1.496 keV
Binding energy	7,526 ±0.0062 keV
Single-particle energy	5,575 ±1.044 keV
Neutron separation energy	5,693 ±1.049 keV
Q value for electron capture	6.931 ±2.041 keV
β⁻ decay energy	-1,508 ±4.506 keV
β⁻ decay energy with neutron	-8,641 ±135 keV
Magnetic dipole moment	0.4 ±0.08 μN

Point at nuclide Decay chain of Curium-243

244CmCurium-244

Classification	z: 96; n: 148; m: 244
Half life	18.11 ±3 a
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; spontaneous fission
Discovery	1950
Mass excess	58,450 ±1.106 keV
Binding energy	7,523 ±0.0045 keV
Single-particle energy	6,012 ±1.222 keV
Neutron separation energy	6,801 ±1.026 keV
Q value for electron capture	-1,428 ±1.8 keV
β⁻ decay energy	-2,262 ±14.35 keV
β⁻ decay energy with neutron	-8,310 ±4.396 keV

Point at nuclide Decay chain of Curium-244

245CmCurium-245

Classification	z: 96; n: 149; m: 245
Half life	8,423 ±74 a
Natural abundance	synthetic nuclide
Spin/parity	7/2+
Decay modes	α decay; spontaneous fission
Discovery	1954
Mass excess	61,000 ±1.149 keV
Binding energy	7,515 ±0.0047 keV
Single-particle energy	6,163 ±1.114 keV
Neutron separation energy	5,518 ±0.4913 keV
Q value for electron capture	-895.9 ±2.208 keV
β⁻ decay energy	-809.3 ±1.496 keV
β⁻ decay energy with neutron	-7,781 ±14.36 keV
Magnetic dipole moment	0.5 ±0.1 μN

Point at nuclide Decay chain of Curium-245

246CmCurium-246

Classification	z: 96; n: 150; m: 246
Half life	4,706 ±40 a
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; spontaneous fission
Discovery	1954
Mass excess	62,610 ±1.525 keV
Binding energy	7,511 ±0.0062 keV
Single-particle energy	6,572 ±1.963 keV
Neutron separation energy	6,458 ±1.217 keV
Q value for electron capture	-2,378 ±18.06 keV
β⁻ decay energy	-1,350 ±60 keV
β⁻ decay energy with neutron	-7,269 ±1.803 keV

Point at nuclide Decay chain of Curium-246

247CmCurium-247

Classification	z: 96; n: 151; m: 247
Half life	1.56·10⁷ ±5 a
Natural abundance	synthetic nuclide
Spin/parity	9/2-
Decay modes	α decay
Discovery	1954
Mass excess	65,530 ±3.797 keV
Binding energy	7,501 ±0.0154 keV
Single-particle energy	6,750 ±18 keV
Neutron separation energy	5,155 ±3.775 keV
Q value for electron capture	-1,620 ±100 keV
β⁻ decay energy	43.58 ±6.324 keV
β⁻ decay energy with neutron	-6,506 ±60.11 keV
Magnetic dipole moment	0.36 ±0.07 μN

Point at nuclide Decay chain of Curium-247

248CmCurium-248

Classification	z: 96; n: 152; m: 248
Half life	348,000 ±6 a
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	α decay; spontaneous fission
Discovery	1956
Mass excess	67,390 ±2.358 keV
Binding energy	7,496 ±0.0095 keV
Single-particle energy	7,049 ±100 keV
Neutron separation energy	6,211 ±3.97 keV
Q value for electron capture	-3,171 ±200 keV
β⁻ decay energy	-738.4 ±50 keV
β⁻ decay energy with neutron	-6,169 ±5.661 keV

Point at nuclide Decay chain of Curium-248

249CmCurium-249

Classification	z: 96; n: 153; m: 249
Half life	64.15 ±3 m
Natural abundance	synthetic nuclide
Spin/parity	1/2+
Decay modes	β⁻ decay
Discovery	1956
Mass excess	70,750 ±2.371 keV
Binding energy	7,485 ±0.0095 keV
Single-particle energy	7,101 ±200 keV
Neutron separation energy	4,713 ±0.25 keV
Q value for electron capture	-2,354 ±298 keV
β⁻ decay energy	904.3 ±2.593 keV
β⁻ decay energy with neutron	-5,452 ±50 keV

Point at nuclide Decay chain of Curium-249

250CmCurium-250

Classification	z: 96; n: 154; m: 250
Half life	8,300 a
Natural abundance	synthetic nuclide
Spin/parity	0+
Decay modes	spontaneous fission; α decay; β⁻ decay
Discovery	1966
Mass excess	72,980 ±10.27 keV
Binding energy	7,478 ±0.0411 keV
Single-particle energy	7,403 ±298 keV
Neutron separation energy	5,832 ±10 keV
β⁻ decay energy	37.58 ±10.64 keV
β⁻ decay energy with neutron	-4,929 ±10.32 keV

Point at nuclide Decay chain of Curium-250

251CmCurium-251

Classification	z: 96; n: 155; m: 251
Half life	16.8 ±2 m
Natural abundance	synthetic nuclide
Spin/parity	(1/2+)
Decay modes	β⁻ decay
Discovery	1978
Mass excess	76,640 ±22.69 keV
Binding energy	7,466 ±0.0904 keV
Neutron separation energy	4,412 ±24.83 keV
β⁻ decay energy	1,420 ±20 keV
β⁻ decay energy with neutron	-4,376 ±22.82 keV

Point at nuclide Decay chain of Curium-251