Talk:Isotopes of tantalum

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This article is part of Wikipedia:Wikiproject Isotopes. Please keep style and phrasings consistent across the set of pages. For later reference and improved reliability, data from all considered multiple sources is collected here. References are denoted by these letters:

  • (A) G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003). — Where this source indicates a speculative value, the # mark is also applied to values with weak assignment arguments from other sources, if grouped together. An asterisk after the A means that a comment of some importance may be available in the original.
  • (B) National Nuclear Data Center, Brookhaven National Laboratory, information extracted from the NuDat 2.1 database. (Retrieved Sept. 2005, from the code of the popup boxes).
  • (C) David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes. — The CRC uses rounded numbers with implied uncertainties, where this concurs with the range of another source it is treated as exactly equal in this comparison.
  • (D) More specific level data from reference B's Levels and Gammas database.
  • (E) Same as B but excitation energy replaced with that from D.
  Z   N refs symbol   half-life                   spin              excitation energy
 73  82 A   |Ta-155  |13(4) µs                   |(11/2-)
 73  82 B   |Ta-155  |12(+4-3) µs                |11/2-
 73  82 C   |Ta-155  |12 µs                      |
 73  83 AB  |Ta-156  |144(24) ms                 |(2-)
 73  83 C   |Ta-156  |0.11 s                     |
 73  83 A   |Ta-156m |360(40) ms                 |(9+)             |100(8) keV
 73  83 E   |Ta-156m |0.36(4) s                  |9+               |102(7) keV
 73  84 AB  |Ta-157  |10.1(4) ms                 |1/2+
 73  84 C   |Ta-157  |10 ms                      |
 73  84 AE  |Ta-157m1|4.3(1) ms                  |11/2-            |22(5) keV
 73  84 A   |Ta-157m2|1.7(1) ms                  |(25/2-)          |1593(9) keV
 73  84 E   |Ta-157m2|1.7(1) ms                  |(25/2-)          |1589(10) keV
 73  85 A   |Ta-158  |49(8) ms                   |(2-)
 73  85 B   |Ta-158  |55(15) ms                  |(2-)
 73  85 C   |Ta-158  |37. ms                     |
 73  85 A   |Ta-158m |36.0(8) ms                 |(9+)             |140(12) keV
 73  85 E   |Ta-158m |36.7(15) ms                |(9+)             |141(9) keV
 73  86 A   |Ta-159  |1.04(9) s                  |(1/2+)
 73  86 B   |Ta-159  |0.83(18) s                 |(1/2-)
 73  86 C   |Ta-159  |0.6 s                      |
 73  86 A   |Ta-159m |514(9) ms                  |(11/2-)          |64(5) keV
 73  86 E   |Ta-159m |515(20) ms                 |(11/2-)          |64(5) keV
 73  87 A   |Ta-160  |1.70(20) s                 |(2#)-
 73  87 B   |Ta-160  |1.55(4) s                  |
 73  87 C   |Ta-160  |1.4 s                      |
 73  87 A   |Ta-160m |1.55(4) s                  |(9)+             |310(90)# keV
 73  87 B   |Ta-160m |1.7(2) s                   |                 |0 MeV
 73  88 A   |Ta-161  |3# s                       |1/2+#
 73  88 B   |Ta-161  |2.89(12) s                 |
 73  88 C   |Ta-161  |2.9 s                      |
 73  88 A   |Ta-161m |2.89(12) s                 |11/2-#           |50(50)# keV
 73  88 D   |Ta-161m |2.89(12) s                 |                 |0 keV
 73  89 A   |Ta-162  |3.57(12) s                 |3+#
 73  89 BC  |Ta-162  |3.57(12) s                 |
 73  90 A   |Ta-163  |10.6(18) s                 |1/2+#
 73  90 BC  |Ta-163  |10.6(18) s                 |
 73  91 ABC |Ta-164  |14.2(3) s                  |(3+)
 73  92 A   |Ta-165  |31.0(15) s                 |5/2-#
 73  92 BC  |Ta-165  |31.0(15) s                 |
 73  92 A   |Ta-165m |                           |9/2-#            |60(30) keV
 73  93 AB  |Ta-166  |34.4(5) s                  |(2)+
 73  93 C   |Ta-166  |34. s                      |
 73  94 A   |Ta-167  |1.33(7) min                |(3/2+)
 73  94 B   |Ta-167  |80(4) s                    |(3/2+)
 73  94 C   |Ta-167  |1.4 min                    |
 73  95 AB  |Ta-168  |2.0(1) min                 |(2-,3+)
 73  95 C   |Ta-168  |2.4 min                    |3+
 73  96 AB  |Ta-169  |4.9(4) min                 |(5/2+)
 73  96 C   |Ta-169  |4.9 min                    |
 73  97 A   |Ta-170  |6.76(6) min                |(3)(+#)
 73  97 BC  |Ta-170  |6.76(6) min                |(3+)
 73  98 ABC |Ta-171  |23.3(3) min                |(5/2-)
 73  99 AB  |Ta-172  |36.8(3) min                |(3+)
 73  99 C   |Ta-172  |36.8 min                   |(3-)
 73 100 AB  |Ta-173  |3.14(13) h                 |5/2-
 73 100 C   |Ta-173  |3.6 h                      |(5/2-)
 73 101 AB  |Ta-174  |1.14(8) h                  |3+
 73 101 C   |Ta-174  |1.12 h                     |(3+)
 73 102 ABC |Ta-175  |10.5(2) h                  |7/2+
 73 103 AB  |Ta-176  |8.09(5) h                  |(1)-
 73 103 C   |Ta-176  |8.1 h                      |1-
 73 103 A   |Ta-176m1|1.1(1) ms                  |(+)              |103.0(10) keV
 73 103 D   |Ta-176m1|1.1(1) ms                  |(+)              |103.0 keV
 73 103 D   |Ta-176m2|3.8(4) µs                  |(14-)            |1372.6(11)+X keV
 73 103 A   |Ta-176m3|0.97(7) ms                 |(20-)            |2820(50) keV
 73 103 D   |Ta-176m3|0.97(7) ms                 |(20-)            |2774.8(15)+X keV
 73 104 ABC |Ta-177  |56.56(6) h                 |7/2+
 73 104 AD  |Ta-177m1|410(7) ns                  |9/2-             |73.36(15) keV
 73 104 AD  |Ta-177m2|3.62(10) µs                |5/2-             |186.15(6) keV
 73 104 AD  |Ta-177m3|5.31(25) µs                |21/2-            |1355.01(19) keV
 73 104 AD  |Ta-177m4|133(4) µs                  |49/2-            |4656.3(5) keV
 73 105 AB  |Ta-178  |9.31(3) min                |1+
 73 105 C   |Ta-178  |9.29 min                   |1+
 73 105 D   |Ta-178m |9.31(3) min                |1+               |Y+0 keV
 73 105 E   |Ta-178m |2.36(8) h                  |(7)-             |X+0 keV
 73 105 A   |Ta-178m |2.36(8) h                  |(7)-             |100(50)# keV
 73 105 C   |Ta-178m |2.4 h                      |(7-)
 73 105 A   |Ta-178m |59(3) ms                   |(15-)            |1570(50)# keV
 73 105 D   |Ta-178m |60(5) ms                   |(15-)            |X+1470.6 keV
 73 105 A   |Ta-178m |290(12) ms                 |(21-)            |3000(50)# keV
 73 106 ABC |Ta-179  |1.82(3) a                  |7/2+
 73 106 D   |Ta-179m1|1.42(8) µs                 |(9/2)-           |30.7(1) keV
 73 106 D   |Ta-179m2|335(45) ns                 |(1/2)+           |520.23(18) keV
 73 106 D   |Ta-179m3|322(16) ns                 |(21/2-)          |1252.61(23) keV
 73 106 AD  |Ta-179m4|9.0(2) ms                  |(25/2+)          |1317.3(4) keV
 73 106 D   |Ta-179m5|1.6(4) µs                  |(23/2-)          |1327.9(4) keV
 73 106 AD  |Ta-179m6|54.1(17) ms                |(37/2+)          |2639.3(5) keV
 73 107 AC  |Ta-180  |8.152(6) h                 |1+
 73 107 B   |Ta-180  |8.154(6) h                 |1+
 73 107 A   |Ta-180m1|STABLE [>1.2E+15 a]        |9-               |75.3(13) keV
 73 107 E   |Ta-180m1|>1.2E+15 a                 |9-               |77.1(8) keV
 73 107 C   |Ta-180m1|>1.2E+15 a                 |(9-)
 73 107 A   |Ta-180m2|45(2) µs                   |15-              |1451.0(10) keV
 73 107 D   |Ta-180m2|31.2(14) µs                |15-              |1452.40(18) keV
 73 107 D   |Ta-180m3|2.0(5) µs                  |(22-)            |3679.0(11) keV
 73 107 D   |Ta-180m4|17(5) µs                   |(23,24,25)       |4171.0+X keV
 73 108 ABC |Ta-181  |STABLE                     |7/2+
 73 108 AD  |Ta-181m1|6.05(12) µs                |9/2-             |6.238(20) keV
 73 108 D   |Ta-181m2|18(1) µs                   |1/2+             |615.21(3) keV
 73 108 A   |Ta-181m3|25(2) µs                   |21/2-            |1485(3) keV
 73 108 A   |Ta-181m4|210(20) µs                 |29/2-            |2230(3) keV
 73 109 ABC |Ta-182  |114.43(3) d                |3-
 73 109 AE  |Ta-182m2|15.84(10) min              |10-              |519.572(18) keV
 73 109 C   |Ta-182m2|15.8 min                   |10-
 73 109 AE  |Ta-182m1|283(3) ms                  |5+               |16.263(3) keV
 73 110 ABC |Ta-183  |5.1(1) d                   |7/2+
 73 110 A   |Ta-183m |107(11) ns                 |9/2-             |73.174(12) keV
 73 110 D   |Ta-183m |107(11) ns                 |(9/2)-           |73.174(12) keV
 73 111 ABC |Ta-184  |8.7(1) h                   |(5-)
 73 112 ABC |Ta-185  |49.4(15) min               |(7/2+)#
 73 112 A   |Ta-185m |>1 ms                      |(21/2-)          |1308(29) keV
 73 113 AB  |Ta-186  |10.5(3) min                |(2-,3-)
 73 113 C   |Ta-186  |10.5 min                   |(3-)
 73 113 B   |Ta-186m |1.54(5) min                |                 |0 MeV
 73 114 A   |Ta-187  |2# min [>300 ns]           |7/2+#
 73 114 B   |Ta-187  |~2 min                     |
 73 115 A   |Ta-188  |20# s [>300 ns]            |
 73 115 B   |Ta-188  |~20 s                      |
 73 116 A   |Ta-189  |3# s [>300 ns]             |7/2+#
 73 116 B   |Ta-189  |3# s                       |(7/2+)
 73 117 AB  |Ta-190  |0.3# s                     |

Femto 12:57, 16 November 2005 (UTC)

Talk[edit]

Yeah! Said: Rursus 13:07, 25 May 2008 (UTC)

Killing the bug[edit]

The article confusingly said:

180mTa is the only naturally occurring nuclear isomer (excluding radiogenic and cosmogenic short-living nuclides). It is also the rarest isotope in the Universe, taking into account the elemental abundance of tantalum and isotopic abundance of 180mTa in the natural mixture of isotopes.

Depends on how to take into account ... I'm not going to analyze the statement, just stating that: of the naturally occurring elements, 180mTa is by no means the rarest nuclide. That goes to some nuclide that we can compute must exist in nature by some weird nuclear process (cold neutron capture from SF 238U some such), but we have no chance in the universe to detect by our current technology. It's the rarest primordial (generated by Big Bang, any supernova or some double neutron star collision or so, and then remaining for some 108 or so) isotope of all elements that have at least one stable isotope. Circa true, even though a few primordial Al-26 atoms may remain from the Solar System birth supernovae... Said: Rursus 13:07, 25 May 2008 (UTC)

Table styles[edit]

Isn't there a way to have the table apply the style across the whole column, rather than specifying the same style every time in every cell? That gets old fast. —Długosz (talk) 23:05, 12 October 2009 (UTC)

meta-stable tantalum[edit]

Hey, I'd love to read more about these nuclear isomers - especially now that I know I actually own an extremely small quantity of the stuff - in capacitors, of course! I remember feeling pretty amazed when I first read about it not that long ago; even more surprised when I found out that the discovery was much longer ago (I guess it didn't make the news... ) Zaphraud (talk) 05:18, 25 March 2011 (UTC)

Why is Ta-180m so stable?[edit]

Can someone add an explanation of why this nuclear isomer (or excited state) is so stable? I would guess that predicted to decay merely means here that the 3 decay modes are calculated to be exoenergetic, but that each one would violate some strong selection rule(s). Can someone point to a reference which says so and explains in more detail? Dirac66 (talk) 20:26, 13 August 2012 (UTC)

You can look at this. It says mostly what we've said. The problem with Ta-180 is that the 180m state is only the third excited state. The two below it have spins of +1 and +2, whereas the 180m state is -9 with this huge spin. It needs to get rid of at least 7 units of spin in a single decay, and 8 to get to the ground state. That makes it 5th-forbidden for beta decay (which could go positron or electron, since it's odd-odd), and in gamma decay, you get a factor of 10^5 in extra lifetime for every unit of angular momentum greater than 1. So we've got to emit one photon with at least 7 units more than that, which takes 10^35 times the lifetime of the 10^-12 sec for a usual gamma decay, which gives 10^23 sec or (ta-dah!) 10^15 years. If use that rule of thumb for Tc-99m, you find it need to change spin by 4 in a gamma decay, and thus is inhibited by an extra spin of 3 over the minimum 1. Multiply 10^-12 by (10^5)^3 = 10^15 and obtain a life time of 1000 seconds or 17 minutes, which isn't all that far from the observed 6 hours. So this all makes a sort of sense. Halfnium-178m3 with the half life of 31 years or so has a spin of 16. However, I don't think it is as inhibited as Ta-180m because (unlike Ta-180m), Hf-178m3 has some intermediate-energy states to decay to (some of them NOT metastable, so you don't seem them in metastable lists). I infer that the nearest of these has a delta-J of 5 which is 4 units inhibited, and that gives you the extra lifetime of 100,000 times that of Tc-99m. Which would be 6 hours times 10^5 = 68 years. Close enough.SBHarris 22:13, 13 August 2012 (UTC)
Thanks. Qualitatively as I thought, but I hadn't known how to do the quantitative estimates which are quite interesting. I see that you have now also expanded the explanation at Isotope#Odd proton-odd neutron.
I will add the van Dommelen link as a reference. Also I will change the phrase is predicted to decay in three ways to has sufficient energy to decay in three ways, in order to avoid suggesting that it is predicted to decay at an observable rate. Dirac66 (talk) 20:29, 22 August 2012 (UTC)