Isotopes of hafnium - AbsoluteAstronomy.com

Natural hafnium
Hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869. Hafnium was the penultimate stable...

(Hf) consists of five 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 (¹⁷⁶Hf, ¹⁷⁷Hf, ¹⁷⁸Hf, ¹⁷⁹Hf, and ¹⁸⁰Hf) and one very long-lived radioisotope, ¹⁷⁴Hf, 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...

of 2×10¹⁵ years. In addition, there are 30 other known radionuclide

Radionuclide

A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...

s, the most stable of which is ¹⁸²Hf with a half-life of 8.9×10⁶ years. No other radioisotope has a half-life over 1.87 days. Most isotopes have half-lives under 1 minute. There are also 27 known nuclear isomer

Nuclear isomer

A nuclear isomer is a metastable state of an atomic nucleus caused by the excitation of one or more of its nucleons . "Metastable" refers to the fact that these excited states have half-lives more than 100 to 1000 times the half-lives of the other possible excited nuclear states...

s, the most stable of which is ^178m3Hf with a half-life of 31 years.

Standard atomic mass: 178.49(2) 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-lifeBold for isotopes with half-lives longer than the age of the universe (nearly stable)	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					daughter isotope(s)Bold for stable isotopes	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
¹⁵³Hf	72	81	152.97069(54)#	400# ms [>200 ns]			1/2+#
^153mHf	750(100)# keV			500# ms			11/2-#
¹⁵⁴Hf	72	82	153.96486(54)#	2(1) sec	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...	¹⁵⁴Lu	0+
¹⁵⁴Hf	72	82	153.96486(54)#	2(1) sec	α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (rare)	¹⁵⁰Yb	0+
¹⁵⁵Hf	72	83	154.96339(43)#	890(120) ms	β⁺	¹⁵⁵Lu	7/2-#
¹⁵⁵Hf	72	83	154.96339(43)#	890(120) ms	α (rare)	¹⁵¹Yb	7/2-#
¹⁵⁶Hf	72	84	155.95936(22)	23(1) ms	α (97%)	¹⁵²Yb	0+
¹⁵⁶Hf	72	84	155.95936(22)	23(1) ms	β⁺ (3%)	¹⁵⁶Lu	0+
^156mHf	1959.0(10) keV			480(40) µs			8+
¹⁵⁷Hf	72	85	156.95840(21)#	115(1) ms	α (86%)	¹⁵³Yb	7/2-
¹⁵⁷Hf	72	85	156.95840(21)#	115(1) ms	β⁺ (14%)	¹⁵⁷Lu	7/2-
¹⁵⁸Hf	72	86	157.954799(19)	2.84(7) sec	β⁺ (55%)	¹⁵⁸Lu	0+
¹⁵⁸Hf	72	86	157.954799(19)	2.84(7) sec	α (45%)	¹⁵⁴Yb	0+
¹⁵⁹Hf	72	87	158.953995(18)	5.20(10) sec	β⁺ (59%)	¹⁵⁹Lu	7/2-#
¹⁵⁹Hf	72	87	158.953995(18)	5.20(10) sec	α (41%)	¹⁵⁵Yb	7/2-#
¹⁶⁰Hf	72	88	159.950684(12)	13.6(2) sec	β⁺ (99.3%)	¹⁶⁰Lu	0+
¹⁶⁰Hf	72	88	159.950684(12)	13.6(2) sec	α (.7%)	¹⁵⁶Yb	0+
¹⁶¹Hf	72	89	160.950275(24)	18.2(5) sec	β⁺ (99.7%)	¹⁶¹Lu	3/2-#
¹⁶¹Hf	72	89	160.950275(24)	18.2(5) sec	α (.3%)	¹⁵⁷Yb	3/2-#
¹⁶²Hf	72	90	161.94721(1)	39.4(9) sec	β⁺ (99.99%)	¹⁶²Lu	0+
¹⁶²Hf	72	90	161.94721(1)	39.4(9) sec	α (.008%)	¹⁵⁸Yb	0+
¹⁶³Hf	72	91	162.94709(3)	40.0(6) sec	β⁺	¹⁶³Lu	3/2-#
¹⁶³Hf	72	91	162.94709(3)	40.0(6) sec	α (10⁻⁴%)	¹⁵⁹Yb	3/2-#
¹⁶⁴Hf	72	92	163.944367(22)	111(8) sec	β⁺	¹⁶⁴Lu	0+
¹⁶⁵Hf	72	93	164.94457(3)	76(4) sec	β⁺	¹⁶⁵Lu	(5/2-)
¹⁶⁶Hf	72	94	165.94218(3)	6.77(30) min	β⁺	¹⁶⁶Lu	0+
¹⁶⁷Hf	72	95	166.94260(3)	2.05(5) min	β⁺	¹⁶⁷Lu	(5/2)-
¹⁶⁸Hf	72	96	167.94057(3)	25.95(20) min	β⁺	¹⁶⁸Lu	0+
¹⁶⁹Hf	72	97	168.94126(3)	3.24(4) min	β⁺	¹⁶⁹Lu	(5/2)-
¹⁷⁰Hf	72	98	169.93961(3)	16.01(13) hr	EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...	¹⁷⁰Lu	0+
¹⁷¹Hf	72	99	170.94049(3)	12.1(4) hr	β⁺	¹⁷¹Lu	7/2(+)
^171mHf	21.93(9) keV			29.5(9) sec	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....	¹⁷¹Hf	1/2(-)
¹⁷²Hf	72	100	171.939448(26)	1.87(3) yr	EC	¹⁷²Lu	0+
^172mHf	2005.58(11) keV			163(3) ns			(8-)
¹⁷³Hf	72	101	172.94051(3)	23.6(1) hr	β⁺	¹⁷³Lu	1/2-
¹⁷⁴Hfprimordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...	72	102	173.940046(3)	2.0(4)×10¹⁵ yr	α	¹⁷⁰Yb	0+	0.0016(1)	0.001619-0.001621
^174m1Hf	1549.3 keV			138(4) ns			(6+)
^174m2Hf	1797.5(20) keV			2.39(4) µs			(8-)
^174m3Hf	1797.5 keV			2.39(4) µs			(8-)
^174m4Hf	3311.7 keV			3.7(2) µs			(14+)
¹⁷⁵Hf	72	103	174.941509(3)	70(2) days	β⁺	¹⁷⁵Lu	5/2-
¹⁷⁶HfUsed in Lutetium-Hafnium dating Radiometric dating Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...	72	104	175.9414086(24)	Observationally StableBelieved to undergo α decay to ¹⁷²Yb			0+	0.0526(7)	0.05206-0.05271
¹⁷⁷Hf	72	105	176.9432207(23)	Observationally StableBelieved to undergo α decay to ¹⁷³Yb			7/2-	0.1860(9)	0.18593-0.18606
^177m1Hf	1315.4504(8) keV			1.09(5) sec			23/2+
^177m2Hf	1342.38(20) keV			55.9(12) µs			(19/2-)
^177m3Hf	2740.02(15) keV			51.4(5) min			37/2-
¹⁷⁸Hf	72	106	177.9436988(23)	Observationally StableBelieved to undergo α decay to ¹⁷⁴Yb			0+	0.2728(7)	0.27278-0.27297
^178m1Hf	1147.423(5) keV			4.0(2) sec			8-
^178m2Hf	2573.5(5) keV			68(2) µs			(14-)
^178m3Hf	2445.69(11) keV			31(1) yr			16+
¹⁷⁹Hf	72	107	178.9458161(23)	Observationally StableBelieved to undergo α decay to ¹⁷⁵Yb			9/2+	0.1362(2)	0.13619-0.1363
^179m1Hf	375.0367(25) keV			18.67(4) sec			1/2-
^179m2Hf	1105.84(19) keV			25.05(25) days			25/2-
¹⁸⁰Hf	72	108	179.9465500(23)	Observationally StableBelieved to undergo α decay to ¹⁷⁶Yb			0+	0.3508(16)	0.35076-0.351
^180m1Hf	1141.48(4) keV			5.47(4) hr			8-
^180m2Hf	1374.15(4) keV			0.57(2) µs			(4-)
^180m3Hf	2425.8(10) keV			15(5) µs			(10+)
^180m4Hf	2486.3(9) keV			10(1) µs			12+
^180m5Hf	2538.3(12) keV			>10 µs			(14+)
^180m6Hf	3599.3(18) keV			90(10) µs			(18-)
¹⁸¹Hf	72	109	180.9491012(23)	42.39(6) days	β^-	¹⁸¹Ta	1/2-
^181m1Hf	595(3) keV			80(5) µs			(9/2+)
^181m2Hf	1040(10) keV			~100 µs			(17/2+)
^181m3Hf	1738(10) keV			1.5(5) ms			(27/2-)
¹⁸²Hf	72	110	181.950554(7)	8.90(9)×10⁶ yr	β^-	¹⁸²Ta	0+
^182mHf	1172.88(18) keV			61.5(15) min	β^- (58%)	¹⁸²Ta	8-
^182mHf	1172.88(18) keV			61.5(15) min	IT (42%)	¹⁸²Hf	8-
¹⁸³Hf	72	111	182.95353(3)	1.067(17) hr	β^-	¹⁸³Ta	(3/2-)
¹⁸⁴Hf	72	112	183.95545(4)	4.12(5) hr	β^-	¹⁸⁴Ta	0+
^184mHf	1272.4(4) keV			48(10) sec	β^-	¹⁸⁴Ta	8-
¹⁸⁵Hf	72	113	184.95882(21)#	3.5(6) min	β^-	¹⁸⁵Ta	3/2-#
¹⁸⁶Hf	72	114	185.96089(32)#	2.6(12) min	β^-	¹⁸⁶Ta	0+
¹⁸⁷Hf	72	115	186.96459(43)#	30# s [>300 ns]
¹⁸⁸Hf	72	116	187.96685(54)#	20# s [>300 ns]			0+

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