Curium-244

Isotopes of curium (₉₆Cm)
SF	–
CD	208Pb
ε	243Am
SF	–
SF	–
SF	–
SF	–
SF	–
α	246Pu
β−	250Bk
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Curium (₉₆Cm) is an artificial element with an atomic number of 96. Because it is an artificial element, a standard atomic weight cannot be given, and it has no stable isotopes. The first isotope synthesized was ²⁴²Cm in 1944, which has 146 neutrons.

There are 19 known radioisotopes ranging from ²³³Cm to ²⁵¹Cm. There are also ten known nuclear isomers. The longest-lived isotope is ²⁴⁷Cm, with half-life 15.6 million years – orders of magnitude longer than that of any known isotope beyond curium, and long enough to study as a possible extinct radionuclide that would be produced by the r-process.^[2]^[3] The longest-lived isomer is ^246mCm with a half-life of 1.12 seconds.

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da) ^{[n 2]}^{[n 3]}	Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope	Spin and parity ^{[n 6]}^{[n 4]}
Nuclide ^{[n 1]}	Excitation energy^{[n 4]}			Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope	Spin and parity ^{[n 6]}^{[n 4]}
²³³Cm	96	137	233.05077(8)	23+13 −6 s	β⁺ (80%)	²³³Am	3/2+#
²³³Cm	96	137	233.05077(8)	23+13 −6 s	α (20%)	²²⁹Pu	3/2+#
²³⁴Cm	96	138	234.05016(2)	52(9) s	β⁺ (71%)	²³⁴Am	0+
					α (27%)	²³⁰Pu
					SF (2%)	(various)
²³⁵Cm^[4]	96	139	235.05143(22)#	300+250 −100 s	β⁺ (99.0%)	²³⁵Am	(5/2+)
²³⁵Cm^[4]	96	139	235.05143(22)#	300+250 −100 s	α (1.0%)	²³¹Pu	(5/2+)
²³⁶Cm	96	140	236.05141(22)#	6.8(8) min	β⁺ (82%)	²³⁶Am	0+
					α (18%)	²³²Pu
					SF (<0.1%)^[5]	(various)
²³⁷Cm^[6]^[4]	96	141	237.05290(22)#	>660 s	β⁺	²³⁷Am	(5/2+)
²³⁷Cm^[6]^[4]	96	141	237.05290(22)#	>660 s	α (<1%)	²³³Pu	(5/2+)
²³⁸Cm^[6]	96	142	238.05303(4)	2.2(4) h	EC (~94%)	²³⁸Am	0+
²³⁸Cm^[6]	96	142	238.05303(4)	2.2(4) h	α (~6%)	²³⁴Pu	0+
²³⁹Cm^[1]	96	143	239.05496(11)#	2.5(4) h	β⁺	²³⁹Am	(7/2−)
²³⁹Cm^[1]	96	143	239.05496(11)#	2.5(4) h	α (6.2x10⁻³%)	²³⁵Pu	(7/2−)
²⁴⁰Cm	96	144	240.0555295(25)	27(1) d	α (99.5%)	²³⁶Pu	0+
					EC (.5%)	²⁴⁰Am
					SF (3.9×10⁻⁶%)	(various)
²⁴¹Cm	96	145	241.0576530(23)	32.8(2) d	EC (99%)	²⁴¹Am	1/2+
²⁴¹Cm	96	145	241.0576530(23)	32.8(2) d	α (1%)	²³⁷Pu	1/2+
²⁴²Cm^{[n 7]}	96	146	242.0588358(20)	162.8(2) d	α^{[n 8]}	²³⁸Pu	0+
					SF (6.33×10⁻⁶%)	(various)
					CD (10⁻¹⁴%)^{[n 9]}	²⁰⁸Pb ³⁴Si
^242mCm	2800(100) keV			180(70) ns
²⁴³Cm	96	147	243.0613891(22)	29.1(1) y	α (99.71%)	²³⁹Pu	5/2+
					EC (.29%)	²⁴³Am
					SF (5.3×10⁻⁹%)	(various)
^243mCm	87.4(1) keV			1.08(3) μs	IT	²⁴³Cm	1/2+
²⁴⁴Cm^{[n 7]}	96	148	244.0627526(20)	18.10(2) y	α	²⁴⁰Pu	0+
²⁴⁴Cm^{[n 7]}	96	148	244.0627526(20)	18.10(2) y	SF (1.34×10⁻⁴%)	(various)	0+
^244m1Cm	1040.188(12) keV			34(2) ms	IT	²⁴⁴Cm	6+
^244m2Cm	1100(900)# keV			>500 ns	SF	(various)
²⁴⁵Cm	96	149	245.0654912(22)	8.5(1)×10³ y	α	²⁴¹Pu	7/2+
²⁴⁵Cm	96	149	245.0654912(22)	8.5(1)×10³ y	SF (6.1×10⁻⁷%)	(various)	7/2+
^245mCm	355.92(10) keV			290(20) ns	IT	²⁴⁵Cm	1/2+
²⁴⁶Cm	96	150	246.0672237(22)	4.76(4)×10³ y	α (99.97%)	²⁴²Pu	0+
²⁴⁶Cm	96	150	246.0672237(22)	4.76(4)×10³ y	SF (.0261%)	(various)	0+
^246mCm	1179.66(13) keV			1.12(0.24) s	IT	²⁴⁶Cm	8−
²⁴⁷Cm	96	151	247.070354(5)	1.56(5)×10⁷ y	α	²⁴³Pu	9/2−
^247m1Cm	227.38(19) keV			26.3(0.3) μs	IT	²⁴⁷Cm	5/2+
^247m2Cm	404.90(3) keV			100.6(0.6) ns	IT	²⁴⁷Cm	1/2+
²⁴⁸Cm	96	152	248.072349(5)	3.48(6)×10⁵ y	α (91.74%)	²⁴⁴Pu	0+
²⁴⁸Cm	96	152	248.072349(5)	3.48(6)×10⁵ y	SF (8.26%)	(various)	0+
^248mCm	1458.1(1) keV			146(18) μs	IT	²⁴⁸Cm	(8−)
²⁴⁹Cm	96	153	249.075953(5)	64.15(3) min	β⁻	²⁴⁹Bk	1/2(+)
^249mCm	48.758(17) keV			23 μs	α	²⁴⁵Pu	(7/2+)
²⁵⁰Cm	96	154	250.078357(12)	8300# y	SF (74%)^{[n 10]}	(various)	0+
					α (18%)	²⁴⁶Pu
					β⁻ (8%)	²⁵⁰Bk
²⁵¹Cm	96	155	251.082285(24)	16.8(2) min	β⁻	²⁵¹Bk	(1/2+)
This table header & footer: view

^ ^mCm – Excited nuclear isomer.
^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^ ^a ^b ^c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^ Modes of decay:

CD: Cluster decay

EC: Electron capture

SF: Spontaneous fission
^ ( ) spin value – Indicates spin with weak assignment arguments.
^ ^a ^b Most common isotopes
^ Theoretically capable of β⁺β⁺ decay to ²⁴²Pu^[1]
^ Heaviest known nuclide to undergo cluster decay
^ The nuclide with the lowest atomic number known to undergo spontaneous fission as the main decay mode

Actinides vs fission products

Actinides and fission products by half-life v t e
Actinides^[7] by decay chain				Half-life range (a)	Fission products of ²³⁵U by yield^[8]
4n	4n + 1	4n + 2	4n + 3	Half-life range (a)	4.5–7%	0.04–1.25%	<0.001%
²²⁸Ra^№				4–6 a		¹⁵⁵Eu^þ
²⁴⁴Cm^ƒ	²⁴¹Pu^ƒ	²⁵⁰Cf	²²⁷Ac^№	10–29 a	⁹⁰Sr	⁸⁵Kr	^113mCd^þ
²³²U^ƒ		²³⁸Pu^ƒ	²⁴³Cm^ƒ	29–97 a	¹³⁷Cs	¹⁵¹Sm^þ	^121mSn
²⁴⁸Bk^[9]	²⁴⁹Cf^ƒ	^242mAm^ƒ		141–351 a	No fission products have a half-life in the range of 100 a–210 ka ... Zdroj:https://en.wikipedia.org?pojem=Curium-244 Text je dostupný za podmienok Creative Commons Attribution/Share-Alike License 3.0 Unported; prípadne za ďalších podmienok. Podrobnejšie informácie nájdete na stránke Podmienky použitia. Navigácia: Veda > Analytika Antropológia Aplikované vedy Bibliometria Dejiny vedy Encyklopédie Filozofia vedy Forenzné vedy Humanitné vedy Knižničná veda Kryogenika Kryptológia Kulturológia Literárna veda Medzidisciplinárne oblasti Metódy kvantitatívnej analýzy Metavedy Metodika Metodológia vedy Náboženstvo a veda Náučná literatúra Podvody vo vede Popularizácia vedy Potravinárstvo Prírodné vedy Pseudoveda Scientometria Spoločenské vedy Teórie Teatrológia Technické vedy Technika Terminológia Umenie Výskum Veda Veda a technika podľa štátu Veda a technika podľa kontinentu Veda a technika podľa roka Veda v kozme Vedci Vedecká literatúra Vedecké databázy Vedecké experimenty Vedecké konferencie Vedecké metódy Vedecké ocenenia Vedecké organizácie Vedecké parky Vedeckí spisovatelia Vzdelávanie Záhady Príbuzné výrazy: Text je dostupný za podmienok Creative Commons Attribution/Share-Alike License 3.0 Unported; prípadne za ďalších podmienok. Podrobnejšie informácie nájdete na stránke Podmienky použitia. www.astronomia.sk \| www.biologia.sk \| www.botanika.sk \| www.dejiny.sk \| www.economy.sk \| www.elektrotechnika.sk \| www.estetika.sk \| www.farmakologia.sk \| www.filozofia.sk \| Fyzika \| www.futurologia.sk \| www.genetika.sk \| www.chemia.sk \| www.lingvistika.sk \| www.politologia.sk \| www.psychologia.sk \| www.sexuologia.sk \| www.sociologia.sk \| www.veda.sk I www.zoologia.sk

[4] Cm – Excited nuclear isomer.

[5] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-6] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[TNN-7] # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[8] Modes of decay:

CD: Cluster decay

EC: Electron capture

SF: Spontaneous fission

[9] ( ) spin value – Indicates spin with weak assignment arguments.

[c-13] Most common isotopes

[14] Theoretically capable of β⁺β⁺ decay to ²⁴²Pu^[1]

[15] Heaviest known nuclide to undergo cluster decay

[16] The nuclide with the lowest atomic number known to undergo spontaneous fission as the main decay mode

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