Isotopes of erbium

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Isotopes of erbium  (68Er)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
160Er synth 28.58 h ε 160Ho
162Er0.139% stable
164Er1.60%stable
165Ersynth10.36 hε 165Ho
166Er33.5%stable
167Er22.9%stable
168Er27.0%stable
169Ersynth9.4 d β 169Tm
170Er14.9%stable
171Ersynth7.516 hβ 171Tm
172Ersynth49.3 hβ 172Tm
Standard atomic weight Ar°(Er)

Naturally occurring erbium (68Er) is composed of six stable isotopes, with 166Er being the most abundant (33.503% natural abundance). Thirty-nine radioisotopes have been characterized with between 74 and 112 neutrons, or 142 to 180 nucleons, with the most stable being 169Er with a half-life of 9.4 days, 172Er with a half-life of 49.3 hours, 160Er with a half-life of 28.58 hours, 165Er with a half-life of 10.36 hours, and 171Er with a half-life of 7.516 hours. All of the remaining radioactive isotopes have half-lives that are less than 3.5 hours, and the majority of these have half-lives that are less than 4 minutes. This element also has numerous meta states, with the most stable being 167mEr (t1/2 = 2.269 seconds).

Contents

The isotopes of erbium range in atomic weight from 141.9723  Da (142Er) to 179.9644 Da (180Er). The primary decay mode before the most abundant stable isotope, 166Er, is electron capture, and the primary mode after is beta decay. The primary decay products before 166Er are holmium isotopes, and the primary products after are thulium isotopes. All isotopes of erbium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

List of isotopes

Nuclide
[n 1]
Z N Isotopic mass (Da) [4]
[n 2] [n 3]
Half-life [1]
[n 4]
Decay
mode
[1]
[n 5]
Daughter
isotope

[n 6]
Spin and
parity [1]
[n 7] [n 4]
Natural abundance (mole fraction)
Excitation energy [n 4] Normal proportion [1] Range of variation
143Er6875142.96655(43)#200# ms9/2−#
144Er6876143.96070(21)#400# ms
[> 200 ns]
0+
145Er6877144.95787(22)#900(200) ms β+ 145Ho1/2+#
β+, p (?%)144Dy
145mEr205(4)# keV1.0(3) sβ+145Ho(11/2-)
β+, p (?%)144Dy
146Er6878145.952418(7)1.7(6) sβ+146Ho0+
β+, p (?%)145Dy
147Er6879146.94996(4)#3.2(12) sβ+147Ho(1/2+)
β+, p (?%)146Dy
147mEr [n 8] 100(50)# keV1.6(2) sβ+147Ho(11/2−)
β+, p (?%)146Dy
148Er6880147.944735(11)#4.6(2) sβ+ (99.85%)148Ho0+
β+, p (0.15%)147Dy
148mEr2.9132(4) MeV13(3) μs IT 148Er(10+)
149Er6881148.94231(3)4(2) sβ+ (93%)149Ho(1/2+)
β+, p (7%)148Dy
149m1Er741.8(2) keV8.9(2) sβ+ (96.3%)149Ho(11/2−)
IT (3.5%)149Er
β+, p (0.18%)148Dy
149m2Er2.6111(3) MeV0.61(8) μsIT149Er(19/2+)
149m3Er3.302(7) MeV4.8(1) μsIT149Er(27/2−)
150Er6882149.937916(18)18.5(7) sβ+150Ho0+
150mEr2.7965(5) MeV2.55(10) μsIT150Er10+
151Er6883150.937449(18)23.5(20) sβ+151Ho(7/2−)
151m1Er2.5860(5) MeV580(20) msIT (95.3%)151Er(27/2−)
β+ (4.7%)151Ho
151m2Er10.2866(10) MeV0.42(5) μsIT151Er(65/2-, 61/2+)
152Er6884151.935050(9)10.3(1) s α (90%)148Dy0+
β+ (10%)152Ho
153Er6885152.935086(10)37.1(2) sα (53%)149Dy7/2−
β+ (47%)153Ho
153m1Er2.7982(10) MeV373(9) nsIT153Er(27/2-)
153m2Er5.2481(10) MeV248(32) nsIT153Er(41/2-)
154Er6886153.932791(5)3.73(9) minβ+ (99.53%)154Ho0+
α (0.47%)150Dy
155Er6887154.933216(7)5.3(3) minβ+ (99.978%)155Ho7/2−
α (0.022%)151Dy
156Er6888155.931066(26)19.5(10) minβ+156Ho0+
α (1.2×10−5%)152Dy
157Er6889156.931923(28)18.65(10) minβ+157Ho3/2−
157mEr155.4(3) keV76(6) msIT157Er9/2+
158Er6890157.929893(27)2.29(6) h EC 158Ho0+
159Er6891158.930691(4)36(1) minβ+159Ho3/2−
159m1Er182.602(24) keV337(14) nsIT159Er9/2+
159m2Er429.05(3) keV590(60) nsIT159Er11/2−
160Er6892159.929077(26)28.58(9) hEC160Ho0+
161Er6893160.930004(9)3.21(3) hβ+161Ho3/2−
161mEr396.44(4) keV7.5(7) μsIT161Er11/2−
162Er6894161.9287873(8) Observationally Stable [n 9] 0+0.00139(5)
162mEr2.02601(13) MeV88(16) nsIT162Er7(-)
163Er6895162.930040(5)75.0(4) minβ+163Ho5/2−
163mEr445.5(6) keV580(100) nsIT163Er(11/2−)
164Er6896163.9292077(8)Observationally Stable [n 10] 0+0.01601(3)
165Er6897164.9307335(10)10.36(4) hEC165Ho5/2−
165m1Er551.3(6) keV250(30) nsIT165Er11/2-
165m2Er1.8230(6) MeV370(40) nsIT165Er(19/2)
166Er6898165.9303011(4)Observationally Stable [n 11] 0+0.33503(36)
167Er6899166.9320562(3)Observationally Stable [n 12] 7/2+0.22869(9)
167mEr207.801(5) keV2.269(6) sIT167Er1/2−
168Er68100167.93237828(28)Observationally Stable [n 13] 0+0.26978(18)
168mEr1.0940383(16) MeV109.0(7) nsIT168Er4-
169Er68101168.9345984(3)9.392(18) dβ169Tm1/2−
169m1Er92.05(10) keV285(20) nsIT169Er(5/2)-
169m2Er243.69(17) keV200(10) nsIT169Er7/2+
170Er68102169.9354719(15)Observationally Stable [n 14] 0+0.14910(36)
171Er68103170.9380374(15)7.516(2) hβ171Tm5/2−
171mEr198.61(9) keV210(10) nsIT171Er1/2−
172Er68104171.939363(4)49.3(5) hβ172Tm0+
172mEr1.5009(3) MeV579(62) nsIT172Er(6+)
173Er68105172.94240(21)#1.434(17) minβ173Tm(7/2−)
174Er68106173.94423(32)#3.2(2) minβ174Tm0+
174mEr1.1115(7) MeV3.9(3) sIT174Er8-
175Er68107174.94777(43)#1.2(3) minβ175Tm9/2+#
176Er68108175.94994(43)#12# s
[>300 ns]
0+
177Er68109176.95399(54)#8# s
[>300 ns]
1/2−#
178Er68110177.95678(64)#4# s
[>300 ns]
0+
179Er68111178.96127(54)#3# s
[>550 ns)]
3/2−#
180Er68112179.96438(54)#2# s
[>550 ns]
0+
This table header & footer:
  1. mEr  Excited nuclear isomer.
  2. ()  Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. #  Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. 1 2 3 #  Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
    p: Proton emission
  6. Bold symbol as daughter  Daughter product is stable.
  7. () spin value  Indicates spin with weak assignment arguments.
  8. Order of ground state and isomer is uncertain.
  9. Believed to undergo α decay to 158Dy or β+β+ to 162Dy with a half-life over 1.40×1014 years
  10. Believed to undergo α decay to 160Dy or β+β+ to 164Dy
  11. Believed to undergo α decay to 162Dy
  12. Believed to undergo α decay to 163Dy
  13. Believed to undergo α decay to 164Dy
  14. Believed to undergo α decay to 166Dy or ββ to 170Yb with a half-life over 4.10×1017 years

See also

Daughter products other than erbium

References

  1. 1 2 3 4 5 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. "Standard Atomic Weights: Erbium". CIAAW. 1999.
  3. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  4. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.