Isotopes of cerium - AbsoluteAstronomy.com

Naturally occurring cerium
Cerium
Cerium is a chemical element with the symbol Ce and atomic number 58. It is a soft, silvery, ductile metal which easily oxidizes in air. Cerium was named after the dwarf planet . Cerium is the most abundant of the rare earth elements, making up about 0.0046% of the Earth's crust by weight...

(Ce) is composed of 4 stable isotope

Isotope

Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

s: ¹³⁶Ce, ¹³⁸Ce, ¹⁴⁰Ce, and ¹⁴²Ce with ¹⁴⁰Ce being the most abundant (88.48% natural abundance

Natural abundance

In chemistry, natural abundance refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table...

); ¹³⁶Ce, ¹³⁸Ce, and ¹⁴²Ce are predicted to undergo double beta decay but this process has never been observed. 35 radioisotopes have been characterized with the most stable being ¹⁴⁴Ce with a half-life of 284.893 days, ¹³⁹Ce with a half-life of 137.640 days, and ¹⁴¹Ce with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 10 meta states.

The isotopes of cerium range in atomic weight

Atomic weight

Atomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element to 1/12 of the mass of an atom of carbon-12...

from 119 u

Atomic mass unit

The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...

(¹¹⁹Ce) to 157 u (¹⁵⁷Ce).

Standard atomic mass: 140.116(1) u

Table

nuclide symbol	Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... )	N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... )	isotopic mass (u)	half-life	decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer....	daughter isotope(s)Bold for stable isotopes	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life		daughter isotope(s)Bold for stable isotopes	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
¹¹⁹Ce	58	61	118.95276(64)#	200# ms	β⁺ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...	¹¹⁹La	5/2+#
¹²⁰Ce	58	62	119.94664(75)#	250# ms	β⁺	¹²⁰La	0+
¹²¹Ce	58	63	120.94342(54)#	1.1(1) s	β⁺	¹²¹La	(5/2)(+#)
¹²²Ce	58	64	121.93791(43)#	2# s	β⁺	¹²²La	0+
¹²²Ce	58	64	121.93791(43)#	2# s	β⁺, p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very...	¹²¹Ba	0+
¹²³Ce	58	65	122.93540(32)#	3.8(2) s	β⁺	¹²³La	(5/2)(+#)
¹²³Ce	58	65	122.93540(32)#	3.8(2) s	β⁺, p	¹²²Ba	(5/2)(+#)
¹²⁴Ce	58	66	123.93041(32)#	9.1(12) s	β⁺	¹²⁴La	0+
¹²⁵Ce	58	67	124.92844(21)#	9.3(3) s	β⁺	¹²⁵La	(7/2-)
¹²⁵Ce	58	67	124.92844(21)#	9.3(3) s	β⁺, p	¹²⁴Ba	(7/2-)
¹²⁶Ce	58	68	125.92397(3)	51.0(3) s	β⁺	¹²⁶La	0+
¹²⁷Ce	58	69	126.92273(6)	29(2) s	β⁺	¹²⁷La	5/2+#
¹²⁸Ce	58	70	127.91891(3)	3.93(2) min	β⁺	¹²⁸La	0+
¹²⁹Ce	58	71	128.91810(3)	3.5(3) min	β⁺	¹²⁹La	(5/2+)
¹³⁰Ce	58	72	129.91474(3)	22.9(5) min	β⁺	¹³⁰La	0+
^130mCe	2453.6(3) keV			100(8) ns			(7-)
¹³¹Ce	58	73	130.91442(4)	10.2(3) min	β⁺	¹³¹La	(7/2+)
^131mCe	61.8(1) keV			5.0(10) min	β⁺	¹³¹La	(1/2+)
¹³²Ce	58	74	131.911460(22)	3.51(11) h	β⁺	¹³²La	0+
^132mCe	2340.8(5) keV			9.4(3) ms	IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer....	¹³²Ce	(8-)
¹³³Ce	58	75	132.911515(18)	97(4) min	β⁺	¹³³La	1/2+
^133mCe	37.1(8) keV			4.9(4) h	β⁺	¹³³La	9/2-
¹³⁴Ce	58	76	133.908925(22)	3.16(4) d	EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...	¹³⁴La	0+
¹³⁵Ce	58	77	134.909151(12)	17.7(3) h	β⁺	¹³⁵La	1/2(+)
^135mCe	445.8(2) keV			20(1) s	IT	¹³⁵Ce	(11/2-)
¹³⁶Ce	58	78	135.907172(14)	Observationally StableTheorized to undergo β⁺β⁺ decay to ¹³⁶Ba with a half-life Half-life Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to... over 38×10¹⁵ years			0+	0.00185(2)	0.00185-0.00186
^136mCe	3095.5(4) keV			2.2(2) µs			10+
¹³⁷Ce	58	79	136.907806(14)	9.0(3) h	β⁺	¹³⁷La	3/2+
^137mCe	254.29(5) keV			34.4(3) h	IT (99.22%)	¹³⁷Ce	11/2-
^137mCe	254.29(5) keV			34.4(3) h	β⁺ (.779%)	¹³⁷La	11/2-
¹³⁸Ce	58	80	137.905991(11)	Observationally StableTheorized to undergo β⁺β⁺ decay to ¹³⁸Ba with a half-life over 150×10¹² years			0+	0.00251(2)	0.00251-0.00254
^138mCe	2129.17(12) keV			8.65(20) ms	IT	¹³⁸Ce	7-
¹³⁹Ce	58	81	138.906653(8)	137.641(20) d	EC	¹³⁹La	3/2+
^139mCe	754.24(8) keV			56.54(13) s	IT	¹³⁹Ce	11/2-
¹⁴⁰CeFission product Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...	58	82	139.9054387(26)	Observationally StableTheoretically capable of spontaneous fission Spontaneous fission Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses...			0+	0.88450(51)	0.88446-0.88449
^140mCe	2107.85(3) keV			7.3(15) µs			6+
¹⁴¹Ce	58	83	140.9082763(26)	32.508(13) d	β^-	¹⁴¹Pr	7/2-
¹⁴²Ce	58	84	141.909244(3)	Observationally StableTheorized to undergo β^-β^- decay to ¹⁴²Nd with a half-life over 50×10¹⁵ years			0+	0.11114(51)	0.11114-0.11114
¹⁴³Ce	58	85	142.912386(3)	33.039(6) h	β^-	¹⁴³Pr	3/2-
¹⁴⁴Ce	58	86	143.913647(4)	284.91(5) d	β^-	^144mPr	0+
¹⁴⁵Ce	58	87	144.91723(4)	3.01(6) min	β^-	¹⁴⁵Pr	(3/2-)
¹⁴⁶Ce	58	88	145.91876(7)	13.52(13) min	β^-	¹⁴⁶Pr	0+
¹⁴⁷Ce	58	89	146.92267(3)	56.4(10) s	β^-	¹⁴⁷Pr	(5/2-)
¹⁴⁸Ce	58	90	147.92443(3)	56(1) s	β^-	¹⁴⁸Pr	0+
¹⁴⁹Ce	58	91	148.9284(1)	5.3(2) s	β^-	¹⁴⁹Pr	(3/2-)#
¹⁵⁰Ce	58	92	149.93041(5)	4.0(6) s	β^-	¹⁵⁰Pr	0+
¹⁵¹Ce	58	93	150.93398(11)	1.02(6) s	β^-	¹⁵¹Pr	3/2-#
¹⁵²Ce	58	94	151.93654(21)#	1.4(2) s	β^-	¹⁵²Pr	0+
¹⁵³Ce	58	95	152.94058(43)#	500# ms [>300 ns]	β^-	¹⁵³Pr	3/2-#
¹⁵⁴Ce	58	96	153.94342(54)#	300# ms [>300 ns]	β^-	¹⁵⁴Pr	0+
¹⁵⁵Ce	58	97	154.94804(64)#	200# ms [>300 ns]	β^-	¹⁵⁵Pr	5/2-#
¹⁵⁶Ce	58	98	155.95126(64)#	150# ms	β^-	¹⁵⁶Pr	0+
¹⁵⁷Ce	58	99	156.95634(75)#	50# ms	β^-	¹⁵⁷Pr	7/2+#

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