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Surely 26 should become 25 not stay as 26.
no, the only mass change in ε is the loss of an electron.
--
metta,
The Sunborn
19:54, 6 April 2006 (UTC)
If a positron were emitted from one of the protons in the proton-proton chain reaction (in the Sun), surely the proton would lose mass, not gain mass, because antimatter does not have negative mass, and furthermore, a neutron is more massive than a proton, so surely the proton must undergo electron capture.-- Lukeelms 00:13, 21 October 2006 (UTC)
Is it realy correct to say that electron capture is the inverse of beta emmission? Beta particals are emmited into the surroundings and can travel several metres, but electron capture involves the nuclius absorbing an electrom previously orbiting the atom.
Perhaps some refferance should be made to the schrodinger equation in this artical explaining that functions with an envolope inside the nuclius will sometimes give small, but non-zero probabilities?
It might be worth mentioning inner bremsstrahlung, a gamma photon being emitted at the expense of the neutrino, especially since this is mentioned in the double electron capture and double beta decay articles (although admittedly the prospect of neutrinoless double capture is more exciting than bremsstrahlung in normal beta decay, given the consequences for the standard model).
However, I have no idea how to fit this into the article. (P.S., why does using even a single German word seem to invariably lead to writing ridiculously-long sentences?) -- 69.107.75.113 08:55, 16 March 2007 (UTC)
It might be illuminating to mention that, because of the shape of the binding energy curve, electron capture is mostly seen at the middle of the periodic table (above the Fe hump), and mostly with the lighter isotopes. While the examples fit this pattern, it isn't exactly obvious.
Also, Co-57 might be a better example, just because cobalt is so much more familiar to people that krypton or rubidium--and because it's probably the most-studied example (thanks to the Mossbauer effect, and the fact that it's just over the Fe hump in the curve). -- 69.107.75.113 09:13, 16 March 2007 (UTC)
The first referential link is broken. Needs to be fixed. —Preceding unsigned comment added by Sean keevey ( talk • contribs) 13:18, 24 March 2008 (UTC)
Is there any reason why the three reactions which are written out towards the top of the article aren't listed as common examples lower down? It's not important, it just seems odd... Djr32 ( talk) 20:58, 16 November 2008 (UTC)
Is this the same thing? ie.: When a high energy-proton collides with an atom, it causes the ejections of an electron from the outer layer of the atom.? -- CyclePat ( talk) 16:09, 6 August 2009 (UTC)
When a proton captures an "orbital" electron, we then have a neutral charged combination of a proton and an electron. Is that combination considered to be identical with a neutron based on the standard model concept? WFPM ( talk) 17:05, 21 May 2011 (UTC)
Am I supposed to worry about the mechanics of how one of the up quarks of the proton changes to a down quark as a result of this capture process? 1: the proton reels in the electron, then we have a proton plus an electron. Then 2: the electron changes an up quark to a down quark?, plus a neutrino? And as individual entities, the neutron is more massive than the proton (plus the electron). Except inside of an atom, I guess. I'm specifically thinking about ec in the context of EO54Xe127 going spontaneously to OE53I127, which is the only reason there is any stable 53Iodine. Any comment? WFPM ( talk) 13:04, 22 May 2011 (UTC) Note that to get to OE53I127 from OO53I126 involves an incremental mass increase of 0.998849 amu's,(for an incremental neutron addition), whereas to get there from EE54Xe126 only requires an increase of 0.99656 amu's for a proton addition. So it takes more energy to add on the neutron than it did for the proton (per the CRC handbook).
Well, as V Smith said "It's complicated aint it?" And I'm thinking about posting a profile chart about the isotopes of Iodine like I did in Talk:Isotopes of lead except in the case of 53 Iodine, there might be some irregularities of data worth discussing. I think most people don't pay much attention to the implication of some of the charts' details and don't think much can be learned from a study of them; and I think a lot could be learned by paying attention and learning the implications of some of the "irregularities" in the details. WFPM ( talk) 20:51, 22 May 2011 (UTC)And as for the "electron capture" situation I see their analogy to the 2 nucleon Deuteron to 2 neutron change situation, and I see no way that could be an exothermic reaction. And did you ever see the May, 1985 National Geographic article and wish to comment? WFPM ( talk) 22:11, 22 May 2011 (UTC)
Well I'm kind of a Science fiction fan/Engineer/free thinker and I go where my interests lead me. And I think that the best way to learn about a 3 dimensional real physical entity is to stick with the best description that you can achieve within the 3 dimensional space plus time continuum, and then try to deal with any unusual details. But I'm with Newton in that I'm partial to the simplest solution. And of course that involves a process of collecting and examining all the data, with particular attention to discrepancies. So when Feynman et al tells me that I should learn about QM including that is not understandable, I think that the time might be better spent rationalizing events in terms of what I think I know rather than trying to learn an alternative concept that he says in not understandable. WFPM ( talk) 03:21, 23 May 2011 (UTC)
I'll give you another hypothetical question. Say I was able to build a tubular enclosure (pipeline) between me and a distant source of light. Is there any reason to doubt that I would be able to see the light source through the pipeline as the distance got longer? WFPM ( talk) 02:00, 25 May 2011 (UTC)
In the Common Examples section, the electron capture half lives of some elements are given, but there is no explanation of the units. For instance, "55Fe - 2.6 a". What is "a"? This may be a standard unit for those with the specific domain knowledge, but lots of people reading this won't know it. 24.79.82.67 ( talk) 15:10, 15 May 2012 (UTC)
As for WFPM's question, as usual, he's assuming that which is not in evidence -- in this case a model of F-18 in which is composed of 9 deuterons. It's not composed of 9 deuterons. That's all that need be said. If you think it is, WFPM, answer your OWN question! S B H arris 01:45, 18 June 2012 (UTC)
There's no mystery why N and P tend to be even: it's just the same in molecules where the Pauli principle tends to make electrons come in pairs since they can sit in the same orbital in a pair with no extra energy cost (one spin up, the other spin down). Neutrons and protons are the same way. Even-P elements are more abundant and have more stable isotopes. Even N isotopes are common for the same reason-- neutron pairing has nothing to do with deuterons-- it's just neutron pairing. No more mysterious than electron pairing, and happens for the same reason. S B H arris 04:26, 18 June 2012 (UTC)
I don't know what you think a "balancing" addition of neutrons is, but I assume you that pairs of neutrons are like pairs of electrons in an atoms. The "pair" is everywhere, with wavefunction spread out over a large nuclear volume. Nucleons don't simply sit there like marbles. And you might think of U-238 as 92 deuterons and 54 extra neutrons, but nobody else does. A nuclear physicist would use the nuclear shell model and guess that U-238 is blessed with 82, 8, and 2 protons in closed proton shells, and 126 and 20 neutrons in closed neutron shells. And that's why U-238 is very nearly stable, and other configurations (+/- a neutron or +/-a proton) are NOT. S B H arris 22:02, 18 June 2012 (UTC)
Well I certainly appreciate your attention and response to my comments about my concepts and I'll have to return to my Kaplan as well as Wikipedia to mull over some of what you tell me. But if I have to have the P's and the N's paired with each other and I'm going to have a hard time explaining why EE4Be8 should require an additional extra n to be stable. and what kind of pairs do you have in OO3Li6? And if equal particles pair in opposing spin conditions, and if closeness of association {packing) is related to reduced free energy content I would have a hard time melding your 3 domains of protons plus 2 domains of neutrons into a EE92U238 composite nucleus with close or closer spacing than Dr Urey's deuteron particle. And I better understand why you are not concerned with the order of presentation of the nucleons within an atom, and given the existence of these domains I don't see why the emission of an alpha particle (two from each domain) is so common. But thank you. WFPM ( talk) 01:38, 19 June 2012 (UTC)
And yet you still don't like a planar structure alpha concept. It has to have some kind of structure. And the problem comes when you try to bind 2 alphas together. So I assumed the neutron did that by binding one corner, because the core of my concept is around a cubic EE4Be8 atom, with added deuterons and balancing extra neutrons. I like Gamow, but I don't like his triple-alpha accumulation concept. And if I could sell the 4Be8 + 2 deuteron concept to get EE6C12 then I move all the alpha created deuteron accumulation processes out to the end of each series like in the Janet periodic table. And after that it's initially loosely bound by extra neutrons and subject to bombardment and unbalanced forces. So the deuterons are accumulated in layers, with each alpha particle being the last 2 deuterons forming an alpha particle on the top. Everywhere else you have side-bonded deuterons, which would be hard to convert to alpha particles. And they're all spinning in synchronous "contact?" with each other and the atom also is spinning. Like in gears and magnetized cylinders. You've got to admit that it's pretty as compared to the popcorn ball alternative. WFPM ( talk) 13:48, 19 June 2012 (UTC) You might note Dr Pauling's comments about "hypothetical structures" in his 1969 "General Chemistry" book page 94 ( ISBN 0-486-65622-5) (paperback) Also page 860.````
Oxygen-16 has no spin; the reason for that is obvious. Now, tell me why O-17, which is 0-16 plus one more neutron, has a spin of 5/2? And why F-17 has the same spin? Looks like either an extra P or N go into a new orbital with total spin of 5/2. But F-18 has a spin of 1. If you put in both a P and an N, the orbital spins cancel, and all you have left is the particle spins of 1/2, pointing in the same direction. Oxygen-18 has no spin at all, just like O-16. Why? The two extra neutrons go into the same neutron-orbital, cancelling orbital momentum, but now one can go in spin-up, the other spin-down, and the net is zero. S B H arris 19:42, 20 June 2012 (UTC)
I don't understand nuclear orbitals, because I used 3/8"dia Neodymium cylindrical magnets to make some of my models and their properties and interrelationships are not compatible with the idea of orbital type motion within the dense nucleus. I also don't understand net spin values like EE4Be8 is Zero (Agree), EO4Be9 is (-3/2)? and OE5B10 is (+3)?. In my models, all the protons spin in one direction and neutrons in the other. However if you turn the model upside down, the noted direction of the spin reverses, and it's possible to have a confusion about spin direction due to that factor. So I can see how the addition of 2 neutrons might be added up to net zero spin. WFPM ( talk) 04:00, 21 June 2012 (UTC) So when we talk about spin, we must admit that they're all spinning, and we're talking about the net spin based on some criteria of direction. WFPM ( talk) 13:44, 4 July 2012 (UTC)
This evening I added a "by whom" to the first paragraph under "Reaction Details"
After more browsing, I found a couple of references that might be relevant to the basic physics, but so far no references to the cosmological assertion.
H. Irnich et al., Phys. Rev. Lett. 75, 4182 (1995).
Yu.A. Litvinov et al., Phys. Lett. B 573, 80 (2003).
Update, same poster: I found a reference that might be suitable. Here's a raw URL: http://articles.adsabs.harvard.edu//full/1964ApJ...139..318B/0000335.000.html
I plan to inquire in the physics forums whether this will serve. — Preceding unsigned comment added by 76.115.88.202 ( talk) 04:22, 9 September 2012 (UTC)
Hi, as an interested layman I would like to know how the capture of an electron can turn a proton into a neutron. Both particles consist only of three quarks. I suppose electron capture turns one up quark into a down quark, thereby quanging the hadron's nature. But where does the electron stay? In the quark? Probably not, quarks are not thought to be compound. In the neutron, between the quarks? That would mean neutrons consist of more than just their three quarks. Well, if neutrons contain an electron, that would explain both their neutral charge and their slightly bigger mass.
If the article is slightly confusing to me, it might very well be my fault. On the other hand, there are more people who want to find out more about these topics, so it might be worth while explaining them. Steinbach ( talk) 23:17, 17 June 2014 (UTC)
I've rewritten the first paragraph to include the X-ray, Auger electron and gamma ray emissions. The distinguishing text at the top of the article was also made more specific, and the caption to the diagram was greatly expanded. The caption makes the diagram box large; this could be turned into a show more tab or removed. Why does the atom in the diagram have one electron each in three shells? Roches ( talk) 03:35, 24 April 2015 (UTC)
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This topic is incomplete without quark-boson representation, the full equations of how the reaction proceeds.
Asgrrr ( talk) 22:02, 15 August 2017 (UTC)
I have curiosity for this thing. If anyone knows, please answer in details. If there is a neutral or non-neutral atom, which is "not-proton-rich" in its nucleus, how the electron capture can occur or how it can be done?
Question from Milind Chatrabhuji from Vadodara, Gujarat, India.
"In the Auger effect, the energy absorbed when the outer electron replaces the inner electron is transferred to an outer electron. "
Should this not be "the energy released?" 165.255.60.165 ( talk) 06:34, 15 October 2022 (UTC)
This page could use an "Electron capture in astrophysics" section.
Sadly, I'm unqualified to write it.
Web search for `"electron capture" astrophysics"' brings up a number of promising surveys which might help. 50.0.193.12 ( talk) 06:25, 6 April 2023 (UTC)
26 13Al |
+
e− → |
26 12Mg |
+
ν e |
In the above as it stands, charge conservation is violated, either write Mg– in the right side, or do not write e– in the left side. 93.150.81.118 ( talk) 16:36, 22 June 2023 (UTC)
In the article it says:
If the energy difference between the parent atom and the daughter atom is less than 1.022 MeV, positron emission is forbidden as not enough decay energy is available to allow it.
But the rest mass of a positron is 0.511 MeV. 1.022 MeV is the minimum energy needed to create an electron-positron pair. — Preceding unsigned comment added by 213.80.51.126 ( talk) 13:47, 27 June 2023 (UTC)
"If the energy difference between the parent atom and the daughter atom is less than 0.511 MeV, positron emission is forbidden as not enough decay energy is available to allow it, and thus electron capture is the sole decay mode. For example, rubidium-83 (37 protons, 46 neutrons) will decay to krypton-83 (36 protons, 47 neutrons) solely by electron capture (the energy difference, or decay energy, is about 0.9 MeV)." This seems to make no sense because 0.9 MeV is *more* than 0.511 MeV. Polar Apposite ( talk) 18:13, 13 July 2023 (UTC)
Previously someone else wrote: 'Electron capture in astrophysics. This page could use an "Electron capture in astrophysics" section.'
I concur. I'm not a physics graduate, so I'm also not volunteering to write it. MathewMunro ( talk) 03:04, 7 January 2024 (UTC)
This table does not include those nuclides with theoretical beta plus energy greater than 1.022 MeV but with no positron emission observed according to NUBASE2020: 85Sr to 85Rb (decay energy 1.0647 MeV), 134Cs to 134Xe (decay energy 1.2333 MeV), 146Pm to 146Nd (decay energy 1.4712 MeV), 146Gd to 146Eu (decay energy 1.0291 MeV), 170Hf to 170Lu (decay energy 1.0563 MeV), 174mLu to 174Yb (decay energy 1.5449 MeV), 192Ir to 192Os (decay energy 1.0473 MeV), 227Pa to 227Th (decay energy 1.02558 MeV) and 252Es to 252Cf (decay energy 1.26 MeV).
Nuclide | A | Z | N | Decay energy (keV) | Branching ratio (%) | Proton excess to the isobar with the lowest energy |
---|---|---|---|---|---|---|
5Li | 5 | 3 | 2 | 292.65 | 0 | 1 |
7Be | 7 | 4 | 3 | 861.893 | 100 | 1 |
37Ar | 37 | 18 | 19 | 813.873 | 100 | 1 |
41Ca | 41 | 20 | 21 | 421.315 | 100 | 1 |
44Ti | 44 | 22 | 22 | 267.63 | 100 | 2 |
49V | 49 | 23 | 26 | 601.856 | 100 | 1 |
51Cr | 51 | 24 | 27 | 752.576 | 100 | 1 |
53Mn | 53 | 25 | 28 | 596.837 | 100 | 1 |
55Fe | 55 | 26 | 29 | 231.212 | 100 | 1 |
57Co | 57 | 27 | 30 | 835.927 | 100 | 1 |
67Ga | 67 | 31 | 36 | 1000.76 | 100 | 1 |
70Ga | 70 | 31 | 39 | 654.56 | 0.41 | -1 |
68Ge | 68 | 32 | 36 | 106.34 | 100 | 2 |
71Ge | 71 | 32 | 39 | 232.506 | 100 | 1 |
73As | 73 | 33 | 40 | 340.83 | 100 | 1 |
76As | 76 | 33 | 43 | 923.543 | 0.02 | -1 |
72Se | 72 | 34 | 38 | 335.4 | 100 | 2 |
75Se | 75 | 34 | 41 | 863.392 | 100 | 1 |
81Kr | 81 | 36 | 45 | 280.801 | 100 | 1 |
83Rb | 83 | 37 | 46 | 906.91 | 100 | 1 |
86Rb | 86 | 37 | 49 | 518.554 | 0.0052 | -1 |
82Sr | 82 | 38 | 44 | 179.82 | 100 | 2 |
90mY | 90 | 39 | 51 | 135.81 | 0 | -1 |
88Zr | 88 | 40 | 48 | 676 | 100 | 2 |
93Mo | 93 | 42 | 51 | 404.78 | 100 | 1 |
97Tc | 97 | 43 | 54 | 320.33 | 100 | 1 |
100Tc | 100 | 43 | 57 | 168.08 | 0.0018 | -1 |
101Rh | 101 | 45 | 56 | 541.7 | 100 | 1 |
100Pd | 100 | 46 | 54 | 358 | 100 | 2 |
103Pd | 103 | 46 | 57 | 543.075 | 100 | 1 |
110Ag | 110 | 47 | 63 | 888.6 | 0.3 | -1 |
109Cd | 109 | 48 | 61 | 214.24 | 100 | 1 |
111In | 111 | 49 | 62 | 861.79 | 100 | 1 |
116In | 116 | 49 | 67 | 469.37 | 0.23 | -1 |
110Sn | 110 | 50 | 60 | 631.1 | 100 | 2 |
119Sb | 119 | 51 | 68 | 590.92 | 100 | 1 |
124Sb | 124 | 51 | 73 | 616.46 | 0 | -1 |
124mSb | 124 | 51 | 73 | 616.46 | 0 | -1 |
118Te | 118 | 52 | 66 | 278.4 | 100 | 2 |
123Te | 123 | 52 | 71 | 52.22 | N/A | 1 |
125I | 125 | 53 | 72 | 185.77 | 100 | 1 |
130I | 130 | 53 | 77 | 419.03 | 0 | -1 |
122Xe | 122 | 54 | 68 | 725 | 100 | 2 |
127Xe | 127 | 54 | 73 | 662.33 | 100 | 1 |
131Cs | 131 | 55 | 76 | 355.42 | 100 | 1 |
136Cs | 136 | 55 | 81 | 86.43 | 0 | -1 |
128Ba | 128 | 56 | 72 | 529.9 | 100 | 2 |
133Ba | 133 | 56 | 77 | 517.499 | 100 | 1 |
133mBa | 133 | 56 | 77 | 805.746 | 0.0096 | 1 |
137La | 137 | 57 | 80 | 620.6 | 100 | 1 |
134Ce | 134 | 58 | 76 | 382.7 | 100 | 2 |
139Ce | 139 | 58 | 81 | 278.88 | 100 | 1 |
142Pr | 142 | 59 | 83 | 745.75 | 0.0164 | -1 |
140Nd | 140 | 60 | 80 | 443.5 | 100 | 2 |
145Pm | 145 | 61 | 84 | 163.37 | 99.99999972 | 1 |
148Pm | 148 | 61 | 87 | 541.51 | 0 | -1 |
150Pm | 150 | 61 | 89 | 86.32 | 0 | -1 |
145Sm | 145 | 62 | 83 | 616.03 | 100 | 2 |
149Eu | 149 | 63 | 86 | 695.36 | 100 | 1 |
154Eu | 154 | 63 | 91 | 717.22 | 0.02 | -1 |
148Gd | 148 | 64 | 84 | 26.67 | 0 | 2 |
151Gd | 151 | 64 | 87 | 464.18 | 99.9999989 | 1 |
153Gd | 153 | 64 | 89 | 483.64 | 100 | 1 |
155Tb | 155 | 65 | 90 | 822.7 | 100 | 1 |
157Tb | 157 | 65 | 92 | 60.052 | 100 | 1 |
160Tb | 160 | 65 | 95 | 105.69 | 0 | -1 |
152Dy | 152 | 66 | 86 | 599.8 | 99.9 | 4 |
159Dy | 159 | 66 | 93 | 365.57 | 100 | 1 |
161Ho | 161 | 67 | 94 | 858.29 | 100 | 1 |
163Ho | 163 | 67 | 96 | 2.555 | 100 | 1 |
164Ho | 164 | 67 | 97 | 986.22 | 60 | 1 |
158Er | 158 | 68 | 90 | 887.2 | 100 | 2 |
160Er | 160 | 68 | 92 | 329.6 | 100 | 2 |
165Er | 165 | 68 | 97 | 376.26 | 100 | 1 |
167Tm | 167 | 69 | 98 | 748.42 | 100 | 1 |
167mTm | 167 | 69 | 98 | 927.90 | 0 | 1 |
170Tm | 170 | 69 | 101 | 313.99 | 0.131 | -1 |
164Yb | 164 | 70 | 94 | 865.7 | 100 | 4 |
166Yb | 166 | 70 | 96 | 305.4 | 100 | 2 |
169Yb | 169 | 70 | 99 | 909.65 | 100 | 1 |
176Lu | 176 | 71 | 105 | 106.77 | 0.45 | -1 |
176mLu | 176 | 71 | 105 | 229.62 | 0.095 | -1 |
172Hf | 172 | 72 | 100 | 337.8 | 100 | 2 |
175Hf | 175 | 72 | 103 | 686.85 | 100 | 1 |
179Ta | 179 | 73 | 106 | 105.622 | 100 | 1 |
180Ta | 180 | 73 | 107 | 852.2 | 86 | 1 |
180mTa | 180 | 73 | 107 | 929.3 | 0 | 1 |
182m2Ta | 182 | 73 | 109 | 144.88 | 0 | -1 |
176W | 176 | 74 | 102 | 723.8 | 100 | 2 |
178W | 178 | 74 | 104 | 91.2 | 100 | 2 |
181W | 181 | 74 | 107 | 187.68 | 100 | 1 |
183Re | 183 | 75 | 108 | 556 | 100 | 1 |
186Re | 186 | 75 | 111 | 579.35 | 7.47 | -1 |
186mRe | 186 | 75 | 111 | 727.55 | 0 | -1 |
182Os | 182 | 76 | 106 | 838 | 100 | 2 |
185Os | 185 | 76 | 109 | 1012.797 | 100 | 1 |
189Ir | 189 | 77 | 112 | 532.3 | 100 | 1 |
188Pt | 188 | 78 | 110 | 505.12 | 99.999974 | 2 |
191Pt | 191 | 78 | 113 | 1008.45 | 100 | 1 |
193Pt | 193 | 78 | 115 | 56.794 | 100 | 1 |
195Au | 195 | 79 | 116 | 226.82 | 100 | 1 |
198Au | 198 | 79 | 119 | 325.57 | 0 | -1 |
192Hg | 192 | 80 | 112 | 765.1 | 100 | 2 |
194Hg | 194 | 80 | 114 | 69.1 | 100 | 2 |
197Hg | 197 | 80 | 117 | 600.11 | 100 | 1 |
201Tl | 201 | 81 | 120 | 481.2 | 100 | 1 |
204Tl | 204 | 81 | 123 | 344.27 | 2.9 | -1 |
200Pb | 200 | 82 | 118 | 804.8 | 100 | 2 |
202Pb | 202 | 82 | 120 | 49.7 | 100 | 2 |
203Pb | 203 | 82 | 121 | 974.62 | 100 | 1 |
205Pb | 205 | 82 | 123 | 50.5 | 100 | 1 |
210mBi | 210 | 83 | 127 | 207.82 | 0 | -1 |
212mPo | 212 | 84 | 128 | 659 | 0 | 0 |
211At | 211 | 85 | 126 | 785.36 | 58.2 | 1 |
213At | 213 | 85 | 128 | 73.93 | 0 | 1 |
216At | 216 | 85 | 131 | 473.199 | 0 | -1 |
216mAt | 216 | 85 | 131 | 634.199 | 0 | -1 |
213Rn | 213 | 86 | 127 | 881.21 | 0 | 2 |
215Rn | 215 | 86 | 129 | 86.55 | 0 | 1 |
217Fr | 217 | 87 | 130 | 656.03 | 0 | 1 |
220Fr | 220 | 87 | 133 | 869.48 | 0 | -1 |
216Ra | 216 | 88 | 128 | 312.1 | <0.00000001 | 2 |
219Ra | 219 | 88 | 131 | 775.87 | 0 | 1 |
223Ac | 223 | 89 | 134 | 591.78 | 1 | 1 |
226Ac | 226 | 89 | 137 | 641.11 | 17 | -1 |
220Th | 220 | 90 | 130 | 917.3 | 0 | 2 |
222Th | 222 | 90 | 132 | 581.5 | 0 | 2 |
225Th | 225 | 90 | 135 | 672.01 | 10 | 1 |
229Pa | 229 | 91 | 138 | 311.46 | 99.52 | 1 |
232Pa | 232 | 91 | 141 | 499.53 | 0.003 | -1 |
228U | 228 | 92 | 136 | 300.5 | 2.5 | 2 |
231U | 231 | 92 | 139 | 381.65 | 99.996 | 1 |
235Np | 235 | 93 | 142 | 124.214 | 99.9974 | 1 |
236Np | 236 | 93 | 143 | 933 | 86.3 | 1 |
238Np | 238 | 93 | 145 | 147.32 | 0 | -1 |
234Pu | 234 | 94 | 140 | 393.1 | 94 | 2 |
237Pu | 237 | 94 | 143 | 220.03 | 99.9958 | 1 |
239Am | 239 | 95 | 144 | 802.11 | 99.99 | 1 |
242Am | 242 | 95 | 147 | 751.295 | 17.3 | 1 |
244Am | 244 | 95 | 149 | 75.4 | 0 | -1 |
238Cm | 238 | 96 | 142 | 972.8 | 90 | 2 |
240Cm | 240 | 96 | 144 | 213.6 | 0.5 | 2 |
241Cm | 241 | 96 | 145 | 767.42 | 99 | 1 |
243Cm | 243 | 96 | 147 | 7.48 | 0.29 | 1 |
245Bk | 245 | 97 | 148 | 810.74 | 99.88 | 1 |
248Bk | 248 | 97 | 151 | 687 | 0 | -1 |
248mBk | 248 | 97 | 151 | 667±50 | 30 | -1 |
244Cf | 244 | 98 | 146 | 763.7 | 25 | 2 |
246Cf | 246 | 98 | 148 | 123.3 | 0.004 | 2 |
247Cf | 247 | 98 | 149 | 646 | 99.965 | 1 |
251Es | 251 | 99 | 152 | 377.58 | 99.5 | 1 |
254Es | 254 | 99 | 155 | 651.2 | 0 | -1 |
254mEs | 254 | 99 | 155 | 731.5 | 0.076 | -1 |
256Es | 256 | 99 | 157 | 150# | 0 | -1 |
250Fm | 250 | 100 | 150 | 847 | 10 | 2 |
253Fm | 253 | 100 | 153 | 335.84 | 88 | 1 |
257Md | 257 | 101 | 156 | 406.73 | 85 | 1 |
260Md | 260 | 101 | 159 | <5 | -1 | |
256No | 256 | 102 | 154 | 208.3 | 0 | 2 |
259No | 259 | 102 | 157 | 486 | 25 | 1 |
262Rf | 262 | 104 | 158 | 270# | 0 | 2 |
267Db | 267 | 105 | 162 | 630# | ? | 1 or 2? |
No such nuclide exist for Z = 2, 5~17, 19, 21, 28, 29, 30, 35, 39, 41, 44, and for Bi and Po there are only isomers (210mBi and 212mAt). Pb and Cm are the only known elements with four isotopes (200,202,203,205Pb and 238,240,241,243Cm) with beta plus energy not exceeding 1.022 MeV; the other elements have at most three. Gd is a near miss, as the beta plus decay energy of 146Gd is barely higher than 1.022 MeV, so there would be no hope to observe its actual positron emissions.
In this table, proton excess means (atomic number of the given nuclide) - (atomic number of its isobar with the lowest energy). Characterizations of proton excesses:
Proton excess 1: Neutron-deficient odd-mass nuclides with the EC products being beta-stable. The only known exceptions are 164Ho, 180Ta, 236Np, and 242Am which are odd-odd.
Proton excess -1: Neutron-rich odd-odd nuclides sandwiched by two beta-stable even-even isobars. The only known exceptions are 90mY, 182mTa and 210mBi whose EC products are not beta-stable, because the energies have 90mY>90Sr>90Y, 182m2Ta>182Hf>182Ta, and similarly 210mBi>210Pb>210Bi.
Proton excess 2 or 4: Neutron-deficient even-even nuclides. The only known exceptions are 145Sm and 213Rn, as witnessed by the low energy difference between 145Sm and 145Nd (779.40 keV) and between 213Rn and 213Po (955.14 keV). Neither 213At → 213Po nor 213Rn → 213At has been observed due to the high alpha-instability of 213At and 213Rn; see here and here. Curiously, both of the neutron numbers (83 and 127) are one plus magic numbers. It is likely that 267Db would be the third such nuclide (see below).
Proton excess 0: Isomers of beta-stable nuclides. The only known example is 212mPo, and the energies have 212mPo>212Bi>212Po.
The only known listed nuclides with proton excess 4 are 152Dy and 164Yb. 266Sg, 270Hs and 272Hs could also be examples (see below). It is very likely that 266Sg, 270Hs and 272Hs are also in the list above, but more precise measurements of atomic masses are required to confirm. For none of these nuclides the process of electron capture has been observed. Their proton excesses:
Nuclide | Zagrebaev et al. prediction | KTUY prediction | ||
---|---|---|---|---|
Isobar with the lowest energy | Proton excess | Isobar with the lowest energy | Proton excess | |
267Db | 267Rf | 1 | 267Lr | 2 |
266Sg? | 266Rf | 2 | 266No | 4 |
270Hs? | 270Rf or 270Sg [1] | 4 or 2 | 270Rf | 4 |
272Hs? | 272Sg | 2 | 272Rf | 4 |
Note that alpha decay is or is estimated to be not ignorable for some of these nuclides with N < 126, i.e., the following nuclides are not stable enough even fully ionized:
Nuclide | A | Z | N | Alpha decay energy (MeV) | Alpha decay half-life (yr) or estimation using Geiger–Nuttall law | |
---|---|---|---|---|---|---|
Estimation 1 [2] | Estimation 2 [3] | |||||
145Pm | 145 | 61 | 84 | 2.32 | 6.3×109 | |
149Eu | 149 | 63 | 86 | 2.40 | 5.0×1010 | 3.8×1010 |
148Gd | 148 | 64 | 84 | 3.27 | 86.9 | |
151Gd | 151 | 64 | 87 | 2.65 | 3.01×107 | |
152Dy | 152 | 66 | 86 | 3.73 | 0.2715 | |
158Er | 158 | 68 | 90 | 2.67 | 8.4×1010 | 2.1×1011 |
176W | 176 | 74 | 102 | 3.34 | 9.5×107 | 3.2×108 |
178W | 176 | 74 | 104 | 3.01 | 2.2×1011 | 6.7×1011 |
182Os | 182 | 76 | 106 | 3.37 | 1.2×109 | 2.9×109 |
188Pt | 188 | 78 | 110 | 4.01 | 1.07×105 | |
192Hg | 192 | 80 | 112 | 3.38 | 6.3×1011 | 6.9×1011 |
129.104.241.214 ( talk) 23:54, 13 February 2024 (UTC)
References
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Surely 26 should become 25 not stay as 26.
no, the only mass change in ε is the loss of an electron.
--
metta,
The Sunborn
19:54, 6 April 2006 (UTC)
If a positron were emitted from one of the protons in the proton-proton chain reaction (in the Sun), surely the proton would lose mass, not gain mass, because antimatter does not have negative mass, and furthermore, a neutron is more massive than a proton, so surely the proton must undergo electron capture.-- Lukeelms 00:13, 21 October 2006 (UTC)
Is it realy correct to say that electron capture is the inverse of beta emmission? Beta particals are emmited into the surroundings and can travel several metres, but electron capture involves the nuclius absorbing an electrom previously orbiting the atom.
Perhaps some refferance should be made to the schrodinger equation in this artical explaining that functions with an envolope inside the nuclius will sometimes give small, but non-zero probabilities?
It might be worth mentioning inner bremsstrahlung, a gamma photon being emitted at the expense of the neutrino, especially since this is mentioned in the double electron capture and double beta decay articles (although admittedly the prospect of neutrinoless double capture is more exciting than bremsstrahlung in normal beta decay, given the consequences for the standard model).
However, I have no idea how to fit this into the article. (P.S., why does using even a single German word seem to invariably lead to writing ridiculously-long sentences?) -- 69.107.75.113 08:55, 16 March 2007 (UTC)
It might be illuminating to mention that, because of the shape of the binding energy curve, electron capture is mostly seen at the middle of the periodic table (above the Fe hump), and mostly with the lighter isotopes. While the examples fit this pattern, it isn't exactly obvious.
Also, Co-57 might be a better example, just because cobalt is so much more familiar to people that krypton or rubidium--and because it's probably the most-studied example (thanks to the Mossbauer effect, and the fact that it's just over the Fe hump in the curve). -- 69.107.75.113 09:13, 16 March 2007 (UTC)
The first referential link is broken. Needs to be fixed. —Preceding unsigned comment added by Sean keevey ( talk • contribs) 13:18, 24 March 2008 (UTC)
Is there any reason why the three reactions which are written out towards the top of the article aren't listed as common examples lower down? It's not important, it just seems odd... Djr32 ( talk) 20:58, 16 November 2008 (UTC)
Is this the same thing? ie.: When a high energy-proton collides with an atom, it causes the ejections of an electron from the outer layer of the atom.? -- CyclePat ( talk) 16:09, 6 August 2009 (UTC)
When a proton captures an "orbital" electron, we then have a neutral charged combination of a proton and an electron. Is that combination considered to be identical with a neutron based on the standard model concept? WFPM ( talk) 17:05, 21 May 2011 (UTC)
Am I supposed to worry about the mechanics of how one of the up quarks of the proton changes to a down quark as a result of this capture process? 1: the proton reels in the electron, then we have a proton plus an electron. Then 2: the electron changes an up quark to a down quark?, plus a neutrino? And as individual entities, the neutron is more massive than the proton (plus the electron). Except inside of an atom, I guess. I'm specifically thinking about ec in the context of EO54Xe127 going spontaneously to OE53I127, which is the only reason there is any stable 53Iodine. Any comment? WFPM ( talk) 13:04, 22 May 2011 (UTC) Note that to get to OE53I127 from OO53I126 involves an incremental mass increase of 0.998849 amu's,(for an incremental neutron addition), whereas to get there from EE54Xe126 only requires an increase of 0.99656 amu's for a proton addition. So it takes more energy to add on the neutron than it did for the proton (per the CRC handbook).
Well, as V Smith said "It's complicated aint it?" And I'm thinking about posting a profile chart about the isotopes of Iodine like I did in Talk:Isotopes of lead except in the case of 53 Iodine, there might be some irregularities of data worth discussing. I think most people don't pay much attention to the implication of some of the charts' details and don't think much can be learned from a study of them; and I think a lot could be learned by paying attention and learning the implications of some of the "irregularities" in the details. WFPM ( talk) 20:51, 22 May 2011 (UTC)And as for the "electron capture" situation I see their analogy to the 2 nucleon Deuteron to 2 neutron change situation, and I see no way that could be an exothermic reaction. And did you ever see the May, 1985 National Geographic article and wish to comment? WFPM ( talk) 22:11, 22 May 2011 (UTC)
Well I'm kind of a Science fiction fan/Engineer/free thinker and I go where my interests lead me. And I think that the best way to learn about a 3 dimensional real physical entity is to stick with the best description that you can achieve within the 3 dimensional space plus time continuum, and then try to deal with any unusual details. But I'm with Newton in that I'm partial to the simplest solution. And of course that involves a process of collecting and examining all the data, with particular attention to discrepancies. So when Feynman et al tells me that I should learn about QM including that is not understandable, I think that the time might be better spent rationalizing events in terms of what I think I know rather than trying to learn an alternative concept that he says in not understandable. WFPM ( talk) 03:21, 23 May 2011 (UTC)
I'll give you another hypothetical question. Say I was able to build a tubular enclosure (pipeline) between me and a distant source of light. Is there any reason to doubt that I would be able to see the light source through the pipeline as the distance got longer? WFPM ( talk) 02:00, 25 May 2011 (UTC)
In the Common Examples section, the electron capture half lives of some elements are given, but there is no explanation of the units. For instance, "55Fe - 2.6 a". What is "a"? This may be a standard unit for those with the specific domain knowledge, but lots of people reading this won't know it. 24.79.82.67 ( talk) 15:10, 15 May 2012 (UTC)
As for WFPM's question, as usual, he's assuming that which is not in evidence -- in this case a model of F-18 in which is composed of 9 deuterons. It's not composed of 9 deuterons. That's all that need be said. If you think it is, WFPM, answer your OWN question! S B H arris 01:45, 18 June 2012 (UTC)
There's no mystery why N and P tend to be even: it's just the same in molecules where the Pauli principle tends to make electrons come in pairs since they can sit in the same orbital in a pair with no extra energy cost (one spin up, the other spin down). Neutrons and protons are the same way. Even-P elements are more abundant and have more stable isotopes. Even N isotopes are common for the same reason-- neutron pairing has nothing to do with deuterons-- it's just neutron pairing. No more mysterious than electron pairing, and happens for the same reason. S B H arris 04:26, 18 June 2012 (UTC)
I don't know what you think a "balancing" addition of neutrons is, but I assume you that pairs of neutrons are like pairs of electrons in an atoms. The "pair" is everywhere, with wavefunction spread out over a large nuclear volume. Nucleons don't simply sit there like marbles. And you might think of U-238 as 92 deuterons and 54 extra neutrons, but nobody else does. A nuclear physicist would use the nuclear shell model and guess that U-238 is blessed with 82, 8, and 2 protons in closed proton shells, and 126 and 20 neutrons in closed neutron shells. And that's why U-238 is very nearly stable, and other configurations (+/- a neutron or +/-a proton) are NOT. S B H arris 22:02, 18 June 2012 (UTC)
Well I certainly appreciate your attention and response to my comments about my concepts and I'll have to return to my Kaplan as well as Wikipedia to mull over some of what you tell me. But if I have to have the P's and the N's paired with each other and I'm going to have a hard time explaining why EE4Be8 should require an additional extra n to be stable. and what kind of pairs do you have in OO3Li6? And if equal particles pair in opposing spin conditions, and if closeness of association {packing) is related to reduced free energy content I would have a hard time melding your 3 domains of protons plus 2 domains of neutrons into a EE92U238 composite nucleus with close or closer spacing than Dr Urey's deuteron particle. And I better understand why you are not concerned with the order of presentation of the nucleons within an atom, and given the existence of these domains I don't see why the emission of an alpha particle (two from each domain) is so common. But thank you. WFPM ( talk) 01:38, 19 June 2012 (UTC)
And yet you still don't like a planar structure alpha concept. It has to have some kind of structure. And the problem comes when you try to bind 2 alphas together. So I assumed the neutron did that by binding one corner, because the core of my concept is around a cubic EE4Be8 atom, with added deuterons and balancing extra neutrons. I like Gamow, but I don't like his triple-alpha accumulation concept. And if I could sell the 4Be8 + 2 deuteron concept to get EE6C12 then I move all the alpha created deuteron accumulation processes out to the end of each series like in the Janet periodic table. And after that it's initially loosely bound by extra neutrons and subject to bombardment and unbalanced forces. So the deuterons are accumulated in layers, with each alpha particle being the last 2 deuterons forming an alpha particle on the top. Everywhere else you have side-bonded deuterons, which would be hard to convert to alpha particles. And they're all spinning in synchronous "contact?" with each other and the atom also is spinning. Like in gears and magnetized cylinders. You've got to admit that it's pretty as compared to the popcorn ball alternative. WFPM ( talk) 13:48, 19 June 2012 (UTC) You might note Dr Pauling's comments about "hypothetical structures" in his 1969 "General Chemistry" book page 94 ( ISBN 0-486-65622-5) (paperback) Also page 860.````
Oxygen-16 has no spin; the reason for that is obvious. Now, tell me why O-17, which is 0-16 plus one more neutron, has a spin of 5/2? And why F-17 has the same spin? Looks like either an extra P or N go into a new orbital with total spin of 5/2. But F-18 has a spin of 1. If you put in both a P and an N, the orbital spins cancel, and all you have left is the particle spins of 1/2, pointing in the same direction. Oxygen-18 has no spin at all, just like O-16. Why? The two extra neutrons go into the same neutron-orbital, cancelling orbital momentum, but now one can go in spin-up, the other spin-down, and the net is zero. S B H arris 19:42, 20 June 2012 (UTC)
I don't understand nuclear orbitals, because I used 3/8"dia Neodymium cylindrical magnets to make some of my models and their properties and interrelationships are not compatible with the idea of orbital type motion within the dense nucleus. I also don't understand net spin values like EE4Be8 is Zero (Agree), EO4Be9 is (-3/2)? and OE5B10 is (+3)?. In my models, all the protons spin in one direction and neutrons in the other. However if you turn the model upside down, the noted direction of the spin reverses, and it's possible to have a confusion about spin direction due to that factor. So I can see how the addition of 2 neutrons might be added up to net zero spin. WFPM ( talk) 04:00, 21 June 2012 (UTC) So when we talk about spin, we must admit that they're all spinning, and we're talking about the net spin based on some criteria of direction. WFPM ( talk) 13:44, 4 July 2012 (UTC)
This evening I added a "by whom" to the first paragraph under "Reaction Details"
After more browsing, I found a couple of references that might be relevant to the basic physics, but so far no references to the cosmological assertion.
H. Irnich et al., Phys. Rev. Lett. 75, 4182 (1995).
Yu.A. Litvinov et al., Phys. Lett. B 573, 80 (2003).
Update, same poster: I found a reference that might be suitable. Here's a raw URL: http://articles.adsabs.harvard.edu//full/1964ApJ...139..318B/0000335.000.html
I plan to inquire in the physics forums whether this will serve. — Preceding unsigned comment added by 76.115.88.202 ( talk) 04:22, 9 September 2012 (UTC)
Hi, as an interested layman I would like to know how the capture of an electron can turn a proton into a neutron. Both particles consist only of three quarks. I suppose electron capture turns one up quark into a down quark, thereby quanging the hadron's nature. But where does the electron stay? In the quark? Probably not, quarks are not thought to be compound. In the neutron, between the quarks? That would mean neutrons consist of more than just their three quarks. Well, if neutrons contain an electron, that would explain both their neutral charge and their slightly bigger mass.
If the article is slightly confusing to me, it might very well be my fault. On the other hand, there are more people who want to find out more about these topics, so it might be worth while explaining them. Steinbach ( talk) 23:17, 17 June 2014 (UTC)
I've rewritten the first paragraph to include the X-ray, Auger electron and gamma ray emissions. The distinguishing text at the top of the article was also made more specific, and the caption to the diagram was greatly expanded. The caption makes the diagram box large; this could be turned into a show more tab or removed. Why does the atom in the diagram have one electron each in three shells? Roches ( talk) 03:35, 24 April 2015 (UTC)
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This topic is incomplete without quark-boson representation, the full equations of how the reaction proceeds.
Asgrrr ( talk) 22:02, 15 August 2017 (UTC)
I have curiosity for this thing. If anyone knows, please answer in details. If there is a neutral or non-neutral atom, which is "not-proton-rich" in its nucleus, how the electron capture can occur or how it can be done?
Question from Milind Chatrabhuji from Vadodara, Gujarat, India.
"In the Auger effect, the energy absorbed when the outer electron replaces the inner electron is transferred to an outer electron. "
Should this not be "the energy released?" 165.255.60.165 ( talk) 06:34, 15 October 2022 (UTC)
This page could use an "Electron capture in astrophysics" section.
Sadly, I'm unqualified to write it.
Web search for `"electron capture" astrophysics"' brings up a number of promising surveys which might help. 50.0.193.12 ( talk) 06:25, 6 April 2023 (UTC)
26 13Al |
+
e− → |
26 12Mg |
+
ν e |
In the above as it stands, charge conservation is violated, either write Mg– in the right side, or do not write e– in the left side. 93.150.81.118 ( talk) 16:36, 22 June 2023 (UTC)
In the article it says:
If the energy difference between the parent atom and the daughter atom is less than 1.022 MeV, positron emission is forbidden as not enough decay energy is available to allow it.
But the rest mass of a positron is 0.511 MeV. 1.022 MeV is the minimum energy needed to create an electron-positron pair. — Preceding unsigned comment added by 213.80.51.126 ( talk) 13:47, 27 June 2023 (UTC)
"If the energy difference between the parent atom and the daughter atom is less than 0.511 MeV, positron emission is forbidden as not enough decay energy is available to allow it, and thus electron capture is the sole decay mode. For example, rubidium-83 (37 protons, 46 neutrons) will decay to krypton-83 (36 protons, 47 neutrons) solely by electron capture (the energy difference, or decay energy, is about 0.9 MeV)." This seems to make no sense because 0.9 MeV is *more* than 0.511 MeV. Polar Apposite ( talk) 18:13, 13 July 2023 (UTC)
Previously someone else wrote: 'Electron capture in astrophysics. This page could use an "Electron capture in astrophysics" section.'
I concur. I'm not a physics graduate, so I'm also not volunteering to write it. MathewMunro ( talk) 03:04, 7 January 2024 (UTC)
This table does not include those nuclides with theoretical beta plus energy greater than 1.022 MeV but with no positron emission observed according to NUBASE2020: 85Sr to 85Rb (decay energy 1.0647 MeV), 134Cs to 134Xe (decay energy 1.2333 MeV), 146Pm to 146Nd (decay energy 1.4712 MeV), 146Gd to 146Eu (decay energy 1.0291 MeV), 170Hf to 170Lu (decay energy 1.0563 MeV), 174mLu to 174Yb (decay energy 1.5449 MeV), 192Ir to 192Os (decay energy 1.0473 MeV), 227Pa to 227Th (decay energy 1.02558 MeV) and 252Es to 252Cf (decay energy 1.26 MeV).
Nuclide | A | Z | N | Decay energy (keV) | Branching ratio (%) | Proton excess to the isobar with the lowest energy |
---|---|---|---|---|---|---|
5Li | 5 | 3 | 2 | 292.65 | 0 | 1 |
7Be | 7 | 4 | 3 | 861.893 | 100 | 1 |
37Ar | 37 | 18 | 19 | 813.873 | 100 | 1 |
41Ca | 41 | 20 | 21 | 421.315 | 100 | 1 |
44Ti | 44 | 22 | 22 | 267.63 | 100 | 2 |
49V | 49 | 23 | 26 | 601.856 | 100 | 1 |
51Cr | 51 | 24 | 27 | 752.576 | 100 | 1 |
53Mn | 53 | 25 | 28 | 596.837 | 100 | 1 |
55Fe | 55 | 26 | 29 | 231.212 | 100 | 1 |
57Co | 57 | 27 | 30 | 835.927 | 100 | 1 |
67Ga | 67 | 31 | 36 | 1000.76 | 100 | 1 |
70Ga | 70 | 31 | 39 | 654.56 | 0.41 | -1 |
68Ge | 68 | 32 | 36 | 106.34 | 100 | 2 |
71Ge | 71 | 32 | 39 | 232.506 | 100 | 1 |
73As | 73 | 33 | 40 | 340.83 | 100 | 1 |
76As | 76 | 33 | 43 | 923.543 | 0.02 | -1 |
72Se | 72 | 34 | 38 | 335.4 | 100 | 2 |
75Se | 75 | 34 | 41 | 863.392 | 100 | 1 |
81Kr | 81 | 36 | 45 | 280.801 | 100 | 1 |
83Rb | 83 | 37 | 46 | 906.91 | 100 | 1 |
86Rb | 86 | 37 | 49 | 518.554 | 0.0052 | -1 |
82Sr | 82 | 38 | 44 | 179.82 | 100 | 2 |
90mY | 90 | 39 | 51 | 135.81 | 0 | -1 |
88Zr | 88 | 40 | 48 | 676 | 100 | 2 |
93Mo | 93 | 42 | 51 | 404.78 | 100 | 1 |
97Tc | 97 | 43 | 54 | 320.33 | 100 | 1 |
100Tc | 100 | 43 | 57 | 168.08 | 0.0018 | -1 |
101Rh | 101 | 45 | 56 | 541.7 | 100 | 1 |
100Pd | 100 | 46 | 54 | 358 | 100 | 2 |
103Pd | 103 | 46 | 57 | 543.075 | 100 | 1 |
110Ag | 110 | 47 | 63 | 888.6 | 0.3 | -1 |
109Cd | 109 | 48 | 61 | 214.24 | 100 | 1 |
111In | 111 | 49 | 62 | 861.79 | 100 | 1 |
116In | 116 | 49 | 67 | 469.37 | 0.23 | -1 |
110Sn | 110 | 50 | 60 | 631.1 | 100 | 2 |
119Sb | 119 | 51 | 68 | 590.92 | 100 | 1 |
124Sb | 124 | 51 | 73 | 616.46 | 0 | -1 |
124mSb | 124 | 51 | 73 | 616.46 | 0 | -1 |
118Te | 118 | 52 | 66 | 278.4 | 100 | 2 |
123Te | 123 | 52 | 71 | 52.22 | N/A | 1 |
125I | 125 | 53 | 72 | 185.77 | 100 | 1 |
130I | 130 | 53 | 77 | 419.03 | 0 | -1 |
122Xe | 122 | 54 | 68 | 725 | 100 | 2 |
127Xe | 127 | 54 | 73 | 662.33 | 100 | 1 |
131Cs | 131 | 55 | 76 | 355.42 | 100 | 1 |
136Cs | 136 | 55 | 81 | 86.43 | 0 | -1 |
128Ba | 128 | 56 | 72 | 529.9 | 100 | 2 |
133Ba | 133 | 56 | 77 | 517.499 | 100 | 1 |
133mBa | 133 | 56 | 77 | 805.746 | 0.0096 | 1 |
137La | 137 | 57 | 80 | 620.6 | 100 | 1 |
134Ce | 134 | 58 | 76 | 382.7 | 100 | 2 |
139Ce | 139 | 58 | 81 | 278.88 | 100 | 1 |
142Pr | 142 | 59 | 83 | 745.75 | 0.0164 | -1 |
140Nd | 140 | 60 | 80 | 443.5 | 100 | 2 |
145Pm | 145 | 61 | 84 | 163.37 | 99.99999972 | 1 |
148Pm | 148 | 61 | 87 | 541.51 | 0 | -1 |
150Pm | 150 | 61 | 89 | 86.32 | 0 | -1 |
145Sm | 145 | 62 | 83 | 616.03 | 100 | 2 |
149Eu | 149 | 63 | 86 | 695.36 | 100 | 1 |
154Eu | 154 | 63 | 91 | 717.22 | 0.02 | -1 |
148Gd | 148 | 64 | 84 | 26.67 | 0 | 2 |
151Gd | 151 | 64 | 87 | 464.18 | 99.9999989 | 1 |
153Gd | 153 | 64 | 89 | 483.64 | 100 | 1 |
155Tb | 155 | 65 | 90 | 822.7 | 100 | 1 |
157Tb | 157 | 65 | 92 | 60.052 | 100 | 1 |
160Tb | 160 | 65 | 95 | 105.69 | 0 | -1 |
152Dy | 152 | 66 | 86 | 599.8 | 99.9 | 4 |
159Dy | 159 | 66 | 93 | 365.57 | 100 | 1 |
161Ho | 161 | 67 | 94 | 858.29 | 100 | 1 |
163Ho | 163 | 67 | 96 | 2.555 | 100 | 1 |
164Ho | 164 | 67 | 97 | 986.22 | 60 | 1 |
158Er | 158 | 68 | 90 | 887.2 | 100 | 2 |
160Er | 160 | 68 | 92 | 329.6 | 100 | 2 |
165Er | 165 | 68 | 97 | 376.26 | 100 | 1 |
167Tm | 167 | 69 | 98 | 748.42 | 100 | 1 |
167mTm | 167 | 69 | 98 | 927.90 | 0 | 1 |
170Tm | 170 | 69 | 101 | 313.99 | 0.131 | -1 |
164Yb | 164 | 70 | 94 | 865.7 | 100 | 4 |
166Yb | 166 | 70 | 96 | 305.4 | 100 | 2 |
169Yb | 169 | 70 | 99 | 909.65 | 100 | 1 |
176Lu | 176 | 71 | 105 | 106.77 | 0.45 | -1 |
176mLu | 176 | 71 | 105 | 229.62 | 0.095 | -1 |
172Hf | 172 | 72 | 100 | 337.8 | 100 | 2 |
175Hf | 175 | 72 | 103 | 686.85 | 100 | 1 |
179Ta | 179 | 73 | 106 | 105.622 | 100 | 1 |
180Ta | 180 | 73 | 107 | 852.2 | 86 | 1 |
180mTa | 180 | 73 | 107 | 929.3 | 0 | 1 |
182m2Ta | 182 | 73 | 109 | 144.88 | 0 | -1 |
176W | 176 | 74 | 102 | 723.8 | 100 | 2 |
178W | 178 | 74 | 104 | 91.2 | 100 | 2 |
181W | 181 | 74 | 107 | 187.68 | 100 | 1 |
183Re | 183 | 75 | 108 | 556 | 100 | 1 |
186Re | 186 | 75 | 111 | 579.35 | 7.47 | -1 |
186mRe | 186 | 75 | 111 | 727.55 | 0 | -1 |
182Os | 182 | 76 | 106 | 838 | 100 | 2 |
185Os | 185 | 76 | 109 | 1012.797 | 100 | 1 |
189Ir | 189 | 77 | 112 | 532.3 | 100 | 1 |
188Pt | 188 | 78 | 110 | 505.12 | 99.999974 | 2 |
191Pt | 191 | 78 | 113 | 1008.45 | 100 | 1 |
193Pt | 193 | 78 | 115 | 56.794 | 100 | 1 |
195Au | 195 | 79 | 116 | 226.82 | 100 | 1 |
198Au | 198 | 79 | 119 | 325.57 | 0 | -1 |
192Hg | 192 | 80 | 112 | 765.1 | 100 | 2 |
194Hg | 194 | 80 | 114 | 69.1 | 100 | 2 |
197Hg | 197 | 80 | 117 | 600.11 | 100 | 1 |
201Tl | 201 | 81 | 120 | 481.2 | 100 | 1 |
204Tl | 204 | 81 | 123 | 344.27 | 2.9 | -1 |
200Pb | 200 | 82 | 118 | 804.8 | 100 | 2 |
202Pb | 202 | 82 | 120 | 49.7 | 100 | 2 |
203Pb | 203 | 82 | 121 | 974.62 | 100 | 1 |
205Pb | 205 | 82 | 123 | 50.5 | 100 | 1 |
210mBi | 210 | 83 | 127 | 207.82 | 0 | -1 |
212mPo | 212 | 84 | 128 | 659 | 0 | 0 |
211At | 211 | 85 | 126 | 785.36 | 58.2 | 1 |
213At | 213 | 85 | 128 | 73.93 | 0 | 1 |
216At | 216 | 85 | 131 | 473.199 | 0 | -1 |
216mAt | 216 | 85 | 131 | 634.199 | 0 | -1 |
213Rn | 213 | 86 | 127 | 881.21 | 0 | 2 |
215Rn | 215 | 86 | 129 | 86.55 | 0 | 1 |
217Fr | 217 | 87 | 130 | 656.03 | 0 | 1 |
220Fr | 220 | 87 | 133 | 869.48 | 0 | -1 |
216Ra | 216 | 88 | 128 | 312.1 | <0.00000001 | 2 |
219Ra | 219 | 88 | 131 | 775.87 | 0 | 1 |
223Ac | 223 | 89 | 134 | 591.78 | 1 | 1 |
226Ac | 226 | 89 | 137 | 641.11 | 17 | -1 |
220Th | 220 | 90 | 130 | 917.3 | 0 | 2 |
222Th | 222 | 90 | 132 | 581.5 | 0 | 2 |
225Th | 225 | 90 | 135 | 672.01 | 10 | 1 |
229Pa | 229 | 91 | 138 | 311.46 | 99.52 | 1 |
232Pa | 232 | 91 | 141 | 499.53 | 0.003 | -1 |
228U | 228 | 92 | 136 | 300.5 | 2.5 | 2 |
231U | 231 | 92 | 139 | 381.65 | 99.996 | 1 |
235Np | 235 | 93 | 142 | 124.214 | 99.9974 | 1 |
236Np | 236 | 93 | 143 | 933 | 86.3 | 1 |
238Np | 238 | 93 | 145 | 147.32 | 0 | -1 |
234Pu | 234 | 94 | 140 | 393.1 | 94 | 2 |
237Pu | 237 | 94 | 143 | 220.03 | 99.9958 | 1 |
239Am | 239 | 95 | 144 | 802.11 | 99.99 | 1 |
242Am | 242 | 95 | 147 | 751.295 | 17.3 | 1 |
244Am | 244 | 95 | 149 | 75.4 | 0 | -1 |
238Cm | 238 | 96 | 142 | 972.8 | 90 | 2 |
240Cm | 240 | 96 | 144 | 213.6 | 0.5 | 2 |
241Cm | 241 | 96 | 145 | 767.42 | 99 | 1 |
243Cm | 243 | 96 | 147 | 7.48 | 0.29 | 1 |
245Bk | 245 | 97 | 148 | 810.74 | 99.88 | 1 |
248Bk | 248 | 97 | 151 | 687 | 0 | -1 |
248mBk | 248 | 97 | 151 | 667±50 | 30 | -1 |
244Cf | 244 | 98 | 146 | 763.7 | 25 | 2 |
246Cf | 246 | 98 | 148 | 123.3 | 0.004 | 2 |
247Cf | 247 | 98 | 149 | 646 | 99.965 | 1 |
251Es | 251 | 99 | 152 | 377.58 | 99.5 | 1 |
254Es | 254 | 99 | 155 | 651.2 | 0 | -1 |
254mEs | 254 | 99 | 155 | 731.5 | 0.076 | -1 |
256Es | 256 | 99 | 157 | 150# | 0 | -1 |
250Fm | 250 | 100 | 150 | 847 | 10 | 2 |
253Fm | 253 | 100 | 153 | 335.84 | 88 | 1 |
257Md | 257 | 101 | 156 | 406.73 | 85 | 1 |
260Md | 260 | 101 | 159 | <5 | -1 | |
256No | 256 | 102 | 154 | 208.3 | 0 | 2 |
259No | 259 | 102 | 157 | 486 | 25 | 1 |
262Rf | 262 | 104 | 158 | 270# | 0 | 2 |
267Db | 267 | 105 | 162 | 630# | ? | 1 or 2? |
No such nuclide exist for Z = 2, 5~17, 19, 21, 28, 29, 30, 35, 39, 41, 44, and for Bi and Po there are only isomers (210mBi and 212mAt). Pb and Cm are the only known elements with four isotopes (200,202,203,205Pb and 238,240,241,243Cm) with beta plus energy not exceeding 1.022 MeV; the other elements have at most three. Gd is a near miss, as the beta plus decay energy of 146Gd is barely higher than 1.022 MeV, so there would be no hope to observe its actual positron emissions.
In this table, proton excess means (atomic number of the given nuclide) - (atomic number of its isobar with the lowest energy). Characterizations of proton excesses:
Proton excess 1: Neutron-deficient odd-mass nuclides with the EC products being beta-stable. The only known exceptions are 164Ho, 180Ta, 236Np, and 242Am which are odd-odd.
Proton excess -1: Neutron-rich odd-odd nuclides sandwiched by two beta-stable even-even isobars. The only known exceptions are 90mY, 182mTa and 210mBi whose EC products are not beta-stable, because the energies have 90mY>90Sr>90Y, 182m2Ta>182Hf>182Ta, and similarly 210mBi>210Pb>210Bi.
Proton excess 2 or 4: Neutron-deficient even-even nuclides. The only known exceptions are 145Sm and 213Rn, as witnessed by the low energy difference between 145Sm and 145Nd (779.40 keV) and between 213Rn and 213Po (955.14 keV). Neither 213At → 213Po nor 213Rn → 213At has been observed due to the high alpha-instability of 213At and 213Rn; see here and here. Curiously, both of the neutron numbers (83 and 127) are one plus magic numbers. It is likely that 267Db would be the third such nuclide (see below).
Proton excess 0: Isomers of beta-stable nuclides. The only known example is 212mPo, and the energies have 212mPo>212Bi>212Po.
The only known listed nuclides with proton excess 4 are 152Dy and 164Yb. 266Sg, 270Hs and 272Hs could also be examples (see below). It is very likely that 266Sg, 270Hs and 272Hs are also in the list above, but more precise measurements of atomic masses are required to confirm. For none of these nuclides the process of electron capture has been observed. Their proton excesses:
Nuclide | Zagrebaev et al. prediction | KTUY prediction | ||
---|---|---|---|---|
Isobar with the lowest energy | Proton excess | Isobar with the lowest energy | Proton excess | |
267Db | 267Rf | 1 | 267Lr | 2 |
266Sg? | 266Rf | 2 | 266No | 4 |
270Hs? | 270Rf or 270Sg [1] | 4 or 2 | 270Rf | 4 |
272Hs? | 272Sg | 2 | 272Rf | 4 |
Note that alpha decay is or is estimated to be not ignorable for some of these nuclides with N < 126, i.e., the following nuclides are not stable enough even fully ionized:
Nuclide | A | Z | N | Alpha decay energy (MeV) | Alpha decay half-life (yr) or estimation using Geiger–Nuttall law | |
---|---|---|---|---|---|---|
Estimation 1 [2] | Estimation 2 [3] | |||||
145Pm | 145 | 61 | 84 | 2.32 | 6.3×109 | |
149Eu | 149 | 63 | 86 | 2.40 | 5.0×1010 | 3.8×1010 |
148Gd | 148 | 64 | 84 | 3.27 | 86.9 | |
151Gd | 151 | 64 | 87 | 2.65 | 3.01×107 | |
152Dy | 152 | 66 | 86 | 3.73 | 0.2715 | |
158Er | 158 | 68 | 90 | 2.67 | 8.4×1010 | 2.1×1011 |
176W | 176 | 74 | 102 | 3.34 | 9.5×107 | 3.2×108 |
178W | 176 | 74 | 104 | 3.01 | 2.2×1011 | 6.7×1011 |
182Os | 182 | 76 | 106 | 3.37 | 1.2×109 | 2.9×109 |
188Pt | 188 | 78 | 110 | 4.01 | 1.07×105 | |
192Hg | 192 | 80 | 112 | 3.38 | 6.3×1011 | 6.9×1011 |
129.104.241.214 ( talk) 23:54, 13 February 2024 (UTC)
References