Isotopes of hafnium
List of isotopes
Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes primordial radionuclide Used in lutetium-hafnium dating Believed to undergo α decay to ¹⁷²Yb Believed to undergo α decay to ¹⁷³Yb Believed to undergo α decay to ¹⁷⁴Yb Believed to undergo α decay to ¹⁷⁵Yb Believed to undergo α decay to ¹⁷⁶Yb

Isotopes of hafnium

Section Title: List of isotopes
Table Section Text: Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes primordial radionuclide Used in lutetium-hafnium dating Believed to undergo α decay to ¹⁷²Yb Believed to undergo α decay to ¹⁷³Yb Believed to undergo α decay to ¹⁷⁴Yb Believed to undergo α decay to ¹⁷⁵Yb Believed to undergo α decay to ¹⁷⁶Yb

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin and parity	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)

excitation energy

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) s	β+	154Lu	0+

α (rare)	150Yb

155Hf	72	83	154.96339(43)#	890(120) ms	β+	155Lu	7/2−#

α (rare)	151Yb

156Hf	72	84	155.95936(22)	23(1) ms	α (97%)	152Yb	0+

β+ (3%)	156Lu

156mHf	1959.0(10) keV	480(40) µs	8+

157Hf	72	85	156.95840(21)#	115(1) ms	α (86%)	153Yb	7/2−

β+ (14%)	157Lu

158Hf	72	86	157.954799(19)	2.84(7) s	β+ (55%)	158Lu	0+

α (45%)	154Yb

159Hf	72	87	158.953995(18)	5.20(10) s	β+ (59%)	159Lu	7/2−#

α (41%)	155Yb

160Hf	72	88	159.950684(12)	13.6(2) s	β+ (99.3%)	160Lu	0+

α (.7%)	156Yb

161Hf	72	89	160.950275(24)	18.2(5) s	β+ (99.7%)	161Lu	3/2−#

α (.3%)	157Yb

162Hf	72	90	161.94721(1)	39.4(9) s	β+ (99.99%)	162Lu	0+

α (.008%)	158Yb

163Hf	72	91	162.94709(3)	40.0(6) s	β+	163Lu	3/2−#

α (10−4%)	159Yb

164Hf	72	92	163.944367(22)	111(8) s	β+	164Lu	0+

165Hf	72	93	164.94457(3)	76(4) s	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) h	EC	170Lu	0+

171Hf	72	99	170.94049(3)	12.1(4) h	β+	171Lu	7/2(+)

171mHf	21.93(9) keV	29.5(9) s	IT	171Hf	1/2(−)

172Hf	72	100	171.939448(26)	1.87(3) y	EC	172Lu	0+

172mHf	2005.58(11) keV	163(3) ns	(8−)

173Hf	72	101	172.94051(3)	23.6(1) h	β+	173Lu	1/2−

174Hf	72	102	173.940046(3)	2.0(4)×1015 y	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	3311.7 keV	3.7(2) µs	(14+)

175Hf	72	103	174.941509(3)	70(2) d	β+	175Lu	5/2−

176Hf	72	104	175.9414086(24)	Observationally Stable	0+	0.0526(7)	0.05206–0.05271

177Hf	72	105	176.9432207(23)	Observationally Stable	7/2−	0.1860(9)	0.18593–0.18606

177m1Hf	1315.4504(8) keV	1.09(5) s	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 Stable	0+	0.2728(7)	0.27278–0.27297

178m1Hf	1147.423(5) keV	4.0(2) s	8−

178m2Hf	2445.69(11) keV	31(1) y	16+

178m3Hf	2573.5(5) keV	68(2) µs	(14−)

179Hf	72	107	178.9458161(23)	Observationally Stable	9/2+	0.1362(2)	0.13619–0.1363

179m1Hf	375.0367(25) keV	18.67(4) s	1/2−

179m2Hf	1105.84(19) keV	25.05(25) d	25/2−

180Hf	72	108	179.9465500(23)	Observationally Stable	0+	0.3508(16)	0.35076–0.351

180m1Hf	1141.48(4) keV	5.47(4) h	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) d	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 y	β−	182Ta	0+

182mHf	1172.88(18) keV	61.5(15) min	β− (58%)	182Ta	8−

IT (42%)	182Hf

183Hf	72	111	182.95353(3)	1.067(17) h	β−	183Ta	(3/2−)

184Hf	72	112	183.95545(4)	4.12(5) h	β−	184Ta	0+

184mHf	1272.4(4) keV	48(10) s	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+

Sentence(s)

¹⁷⁸ᵐ²Hf has a half-life of 31 years.

final_sentence: ¹⁷⁸ᵐ²Hf has a half-life of 31 years.