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Isotopes of beryllium: Difference between revisions

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{{Short description|Nuclides with atomic number of 4 but with different mass numbers}}
{{Short description|none}}
{{more citations needed|date=May 2018}}
{{more citations needed|date=May 2018}}
{{Infobox beryllium isotopes}}
{{Infobox beryllium isotopes}}
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Note: Please change it so that it says that beryllium-8 decays into 2x helium-4, not 1x, since helium-4 is an alpha particle, and another helium-4 is left. Remove this note when this has been done. The *product"is helium-4, so it is correct. This is not the reaction formula (which should balance) -->
Note: Please change it so that it says that beryllium-8 decays into 2x helium-4, not 1x, since helium-4 is an alpha particle, and another helium-4 is left. Remove this note when this has been done. The *product"is helium-4, so it is correct. This is not the reaction formula (which should balance) -->


[[Beryllium]] (<sub>4</sub>Be) has 11 known [[isotope]]s and 3 known [[nuclear isomer|isomers]], but only one of these isotopes ({{SimpleNuclide|Beryllium|9}}) is stable and a [[primordial nuclide]]. As such, beryllium is considered a [[monoisotopic element]]. It is also a [[mononuclidic element]], because its other isotopes have such short half-lives that none are primordial and their abundance is very low ([[standard atomic weight]] is {{val|9.0121831|(5)}}). Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons. There are 25 other monoisotopic elements but all have odd atomic numbers, and even numbers of neutrons.
[[Beryllium]] (<sub>4</sub>Be) has 11 known [[Isotope|isotopes]] and 3 known [[nuclear isomer|isomers]], but only one of these isotopes ({{SimpleNuclide|Beryllium|9}}) is stable and a [[primordial nuclide]]. As such, beryllium is considered a [[monoisotopic element]]. It is also a [[mononuclidic element]], because its other isotopes have such short half-lives that none are primordial and their abundance is very low ([[standard atomic weight]] is {{val|9.0121831|(5)}}). Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons. There are 25 other monoisotopic elements but all have odd atomic numbers, and even numbers of neutrons.


Of the 10 [[radioisotope]]s of beryllium, the most stable are {{SimpleNuclide|Beryllium|10}} with a half-life of {{val|1.387|(12)}} million years{{refn|group=nb|name=tropical|Note that NUBASE2020 uses the <em>tropical</em> year to convert between years and other units of time, not the [[Gregorian year]]. The relationship between years and other time units in NUBASE2020 is as follows: {{nowrap|1=1 y = 365.2422 d = 31 556 926 s}} }} and {{SimpleNuclide|Beryllium|7}} with a half-life of {{val|53.22|(6)|u=days}}. All other radioisotopes have half-lives under {{val|15|u=seconds}}, most under {{val|30|u=milliseconds}}. The least stable isotope is {{SimpleNuclide|Beryllium|16}}, with a half-life of {{val|650|(130)|u=yoctoseconds}}.
Of the 10 [[radionuclide|radioisotopes]] of beryllium, the most stable are {{SimpleNuclide|Beryllium|10}} with a half-life of {{val|1.387|(12)}} million years{{refn|group=nb|name=tropical|Note that NUBASE2020 uses the <em>tropical</em> year to convert between years and other units of time, not the [[Gregorian year]]. The relationship between years and other time units in NUBASE2020 is as follows: {{nowrap|1=1 y = 365.2422 d = 31 556 926 s}} }} and {{SimpleNuclide|Beryllium|7}} with a half-life of {{val|53.22|(6)|u=days}}. All other radioisotopes have half-lives under {{val|15|u=seconds}}, most under {{val|30|u=milliseconds}}. The least stable isotope is {{SimpleNuclide|Beryllium|16}}, with a half-life of {{val|650|(130)|u=yoctoseconds}}.


The 1:1 [[neutron–proton ratio]] seen in stable isotopes of many light elements (up to [[oxygen]], and in elements with even atomic number up to [[calcium]]) is prevented in beryllium by the extreme instability of {{SimpleNuclide|link=yes|Beryllium|8}} toward [[alpha decay]], which is favored due to the extremely tight binding of [[helium#The related stability of the helium-4 nucleus and electron shell|{{SimpleNuclide|Helium|4}}]] nuclei. The half-life for the decay of {{SimpleNuclide|Beryllium|8}} is only {{val|81.9|(3.7)|u=attoseconds}}.
The 1:1 [[neutron–proton ratio]] seen in stable isotopes of many light elements (up to [[oxygen]], and in elements with even atomic number up to [[calcium]]) is prevented in beryllium by the extreme instability of {{SimpleNuclide|link=yes|Beryllium|8}} toward [[alpha decay]], which is favored due to the extremely tight binding of [[helium#Related stability of the helium-4 nucleus and electron shell|{{SimpleNuclide|Helium|4}}]] nuclei. The half-life for the decay of {{SimpleNuclide|Beryllium|8}} is only {{val|81.9|(3.7)|u=attoseconds}}.


Beryllium is prevented from having a stable isotope with 4 protons and 6 neutrons by the very large mismatch in neutron–proton ratio for such a light element. Nevertheless, this isotope, [[beryllium-10|{{SimpleNuclide|Beryllium|10}}]], has a half-life of {{val|1.387|(12)}} million years{{refn|group=nb|name=tropical}}, which indicates unusual stability for a light isotope with such a large neutron/proton imbalance. Other possible beryllium isotopes have even more severe mismatches in neutron and proton number, and thus are even less stable.
Beryllium is prevented from having a stable isotope with 4 protons and 6 neutrons by the very lopsided neutron–proton ratio for such a light element. Nevertheless, this isotope, [[beryllium-10|{{SimpleNuclide|Beryllium|10}}]], has a half-life of {{val|1.387|(12)}} million years,{{refn|group=nb|name=tropical}} which indicates unusual stability for a light isotope with such a large neutron/proton imbalance. Other possible beryllium isotopes have even more severe mismatches in neutron and proton number, and thus are even less stable.


Most {{SimpleNuclide|Beryllium|9}} in the universe is thought to be formed by cosmic ray nucleosynthesis from [[cosmic ray spallation]] in the period between the [[Big Bang]] and the formation of the solar system. The isotopes {{SimpleNuclide|Beryllium|7}}, with a half-life of {{val|53.22|(6)|u=d}}, and {{SimpleNuclide|Beryllium|10}} are both [[cosmogenic nuclides]] because they are made on a recent timescale in the solar system by spallation,<ref name="7Be-Mishra">{{Cite journal|last2=Marhas|first2=Kuljeet Kaur|last1=Mishra|first1=Ritesh Kumar|date=2019-03-25|title=Meteoritic evidence of a late superflare as source of 7 Be in the early Solar System|journal=Nature Astronomy|volume=3|issue=6|language=en|pages=498–505|doi=10.1038/s41550-019-0716-0|issn=2397-3366}}</ref> like [[carbon-14|{{SimpleNuclide|Carbon|14}}]]. These two radioisotopes of beryllium in the atmosphere track the [[sun spot]] cycle and solar activity, since this affects the magnetic field that shields the Earth from cosmic rays. The rate at which the short-lived {{SimpleNuclide|Beryllium|7}} is transferred from the air to the ground is controlled in part by the weather. {{SimpleNuclide|Beryllium|7}} decay in the sun is one of the sources of [[solar neutrino]]s, and the first type ever detected using the [[Homestake experiment]]. Presence of {{SimpleNuclide|Beryllium|7}} in sediments is often used to establish that they are fresh, i.e. less than about 3–4 months in age, or about two half-lives of {{SimpleNuclide|Beryllium|7}}.
Most {{SimpleNuclide|Beryllium|9}} in the universe is thought to be formed by cosmic ray nucleosynthesis from [[cosmic ray spallation]] in the period between the [[Big Bang]] and the formation of the Solar System. The isotopes {{SimpleNuclide|Beryllium|7}}, with a half-life of {{val|53.22|(6)|u=d}}, and {{SimpleNuclide|Beryllium|10}} are both [[cosmogenic nuclide]]s because they are made on a recent timescale in the Solar System by spallation,<ref name="7Be-Mishra">{{Cite journal|last2=Marhas|first2=Kuljeet Kaur|last1=Mishra|first1=Ritesh Kumar|date=2019-03-25|title=Meteoritic evidence of a late superflare as source of 7 Be in the early Solar System|journal=Nature Astronomy|volume=3|issue=6|language=en|pages=498–505|doi=10.1038/s41550-019-0716-0|bibcode=2019NatAs...3..498M|s2cid=126552874|issn=2397-3366}}</ref> like [[carbon-14|{{SimpleNuclide|Carbon|14}}]].

⚫
[[File:Be7fromcosmicrays.png|center|thumb|500px|The rate of delivery of {{SimpleNuclide|Beryllium|7}} from the air to the ground in Japan (source M. Yamamoto ''et al.'', ''Journal of Environmental Radioactivity'', 2006, '''8''', 110–131)]]


== List of isotopes ==
== List of isotopes ==
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|notes=m, resonance, unc(), mass#, spin(), daughter-st, EC, IT, n, p
|notes=m, resonance, unc(), mass#, spin(), daughter-st, EC, IT, n, p
}}
}}
|-id=Beryllium-5
|-
| {{SimpleNuclide|Beryllium|5}}<ref group="n" name="unconfirmed">This isotope has not yet been observed; given data is inferred or estimated from periodic trends.</ref>
⚫
| {{SimpleNuclide|Beryllium|5}}
|4
|4
|1
|1
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|
|
| [[proton emission|p]] ?<ref group="n" name="decay mode 1">Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.</ref>
| [[proton emission|p]] ?<ref group="n" name="decay mode 1">Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.</ref>
| {{SimpleNuclide|Lithium|4}}
| {{SimpleNuclide|Lithium|4}} ?
| (1/2+)#
| (1/2+)#
|
|
|-id=Beryllium-6
|
|-
| {{SimpleNuclide|Beryllium|6}}
| {{SimpleNuclide|Beryllium|6}}
|4
|4
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| '''{{SimpleNuclide|Helium|4}}'''
| '''{{SimpleNuclide|Helium|4}}'''
| 0+
| 0+
|
|
|
|-
|-
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| {{val|7.01692871|(8)}}
| {{val|7.01692871|(8)}}
| {{val|53.22|(6)|u=d}}
| {{val|53.22|(6)|u=d}}
| [[electron capture|EC]]
| [[Electron capture|ε]]
| '''{{SimpleNuclide|Lithium|7}}'''
| '''{{SimpleNuclide|Lithium|7}}'''
| 3/2−
| 3/2−
| Trace<ref group="n" name="t">[[cosmogenic]] nuclide</ref>
| Trace<ref group="n" name="t">[[cosmogenic]] nuclide</ref>
|
|-
|-
| [[Beryllium-8|{{SimpleNuclide|Beryllium|8}}]]<ref group="n">Intermediate product of [[triple alpha process]] in [[stellar nucleosynthesis]] as part of the path producing '''[[carbon-12|<sup>12</sup>C]]'''</ref>
| [[Beryllium-8|{{SimpleNuclide|Beryllium|8}}]]<ref group="n">Intermediate product of [[triple alpha process]] in [[stellar nucleosynthesis]] as part of the path producing '''[[carbon-12|<sup>12</sup>C]]'''</ref>
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| {{val|8.00530510|(4)}}
| {{val|8.00530510|(4)}}
| {{val|81.9|(3.7)|u=as}}<br/>[{{val|5.58|(25)|u=eV}}]
| {{val|81.9|(3.7)|u=as}}<br/>[{{val|5.58|(25)|u=eV}}]
| α<ref group="n">Also often considered [[spontaneous fission]], as {{SimpleNuclide|Beryllium|8}} splits into two equal {{SimpleNuclide|Helium|4}} nuclei</ref>
| α
| '''{{SimpleNuclide|Helium|4}}'''
| '''{{SimpleNuclide|Helium|4}}'''
| 0+
| 0+
|
|
|-id=Beryllium-8m
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|8|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|8|m}}
| colspan="3" style="text-indent:2em" | {{val|16626|(3)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|16626|(3)|u=keV}}
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| 2+
| 2+
|
|
|-id=Beryllium-9
|
|-
| {{SimpleNuclide|Beryllium|9}}
| {{SimpleNuclide|Beryllium|9}}
|4
|4
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| 3/2−
| 3/2−
| 1
| 1
|-id=Beryllium-9m
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|9|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|9|m}}
| colspan="3" style="text-indent:2em" | {{val|14390.3|(1.7)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|14390.3|(1.7)|u=keV}}
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|
|
| 3/2−
| 3/2−
|
|
|
|-
|-
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| 0+
| 0+
| Trace<ref group="n" name="t" />
| Trace<ref group="n" name="t" />
|-id=Beryllium-11
|
|-
| rowspan=3|{{SimpleNuclide|Beryllium|11}}<ref group="n">Has 1 [[halo nucleus|halo]] neutron</ref>
| rowspan=3|{{SimpleNuclide|Beryllium|11}}<ref group="n">Has 1 [[halo nucleus|halo]] neutron</ref>
| rowspan=3|4
| rowspan=3|4
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| '''{{SimpleNuclide|Boron|11}}'''
| '''{{SimpleNuclide|Boron|11}}'''
| rowspan=3|1/2+
| rowspan=3|1/2+
| rowspan=3|
| rowspan=3|
| rowspan=3|
|-
|-
| β<sup>−</sup>[[alpha decay|α]] ({{val|3.3|(1)|u=%}})
| [[Alpha decay|β<sup>−</sup>α]] ({{val|3.3|(1)|u=%}})
| '''{{SimpleNuclide|Lithium|7}}'''
| '''{{SimpleNuclide|Lithium|7}}'''
|-
|-
| β<sup>−</sup>p ({{val|0.0013|(3)|u=%}}) <!--NUBASE lists β−, proton emission-->
| β<sup>−</sup>p ({{val|0.0013|(3)|u=%}})
| {{SimpleNuclide|Beryllium|10}}
| {{SimpleNuclide|Beryllium|10}}
|-id=Beryllium-11m
|-
| β<sup>-</sup>n ?<ref group="n" name="decay mode 1" />
| {{SimpleNuclide|Boron|12}}
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|11|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|11|m}}
| colspan="3" style="text-indent:2em" | {{val|21158|(20)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|21158|(20)|u=keV}}
| {{val|0.93|(13)|u=zs}}<br/>[{{val|500|(75)|u=keV}}]
| {{val|0.93|(13)|u=zs}}<br/>[{{val|500|(75)|u=keV}}]
| [[Isomeric transition|IT]] ?<ref group="n" name="decay mode 1" />
| [[Nuclear isomer#Decay processes|IT]] ?<ref group="n" name="decay mode 1" />
| {{SimpleNuclide|Beryllium|11}}
| {{SimpleNuclide|Beryllium|11}} ?
| 3/2−
| 3/2−
|
|
|-id=Beryllium-12
|
|-
| rowspan=2|{{SimpleNuclide|Beryllium|12}}
| rowspan=2|{{SimpleNuclide|Beryllium|12}}
| rowspan=2|4
| rowspan=2|4
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| {{SimpleNuclide|Boron|12}}
| {{SimpleNuclide|Boron|12}}
| rowspan=2|0+
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
| rowspan=2|
|-
|-
| β<sup>−</sup>n ({{val|0.50|(3)|u=%}})
| β<sup>−</sup>n ({{val|0.50|(3)|u=%}})
| '''{{SimpleNuclide|Boron|11}}'''
| '''{{SimpleNuclide|Boron|11}}'''
|-id=Beryllium-12m
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|12|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|12|m}}
| colspan="3" style="text-indent:2em" | {{val|2251|(1)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|2251|(1)|u=keV}}
| {{val|233|(7)|u=ns}}
| {{val|233|(7)|u=ns}}
| [[Isomeric transition|IT]]
| [[Nuclear isomer#Decay processes|IT]]
| {{SimpleNuclide|Beryllium|12}}
| {{SimpleNuclide|Beryllium|12}}
| 0+
| 0+
|
|
|-id=Beryllium-13
|
|-
| {{SimpleNuclide|Beryllium|13}}
| {{SimpleNuclide|Beryllium|13}}
|4
|4
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| {{val|1.0|(7)|u=zs}}
| {{val|1.0|(7)|u=zs}}
| [[neutron emission|n]] ?<ref group="n" name="decay mode 1" />
| [[neutron emission|n]] ?<ref group="n" name="decay mode 1" />
| {{SimpleNuclide|Beryllium|12}}
| {{SimpleNuclide|Beryllium|12}} ?
| (1/2−)
| (1/2−)
|
|
|-id=Beryllium-13m
|
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|13|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|13|m}}
| colspan="3" style="text-indent:2em" | {{val|1500|(50)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|1500|(50)|u=keV}}
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| (5/2+)
| (5/2+)
|
|
|-id=Beryllium-14
|
|-
| rowspan=5|{{SimpleNuclide|Beryllium|14}}<ref group="n">Has 4 halo neutrons</ref>
| rowspan=5|{{SimpleNuclide|Beryllium|14}}<ref group="n">Has 4 halo neutrons</ref>
| rowspan=5|4
| rowspan=5|4
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| {{SimpleNuclide|Boron|13}}
| {{SimpleNuclide|Boron|13}}
| rowspan=5|0+
| rowspan=5|0+
| rowspan=5|
| rowspan=5|
| rowspan=5|
|-
|-
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| {{SimpleNuclide|Boron|12}}
| {{SimpleNuclide|Boron|12}}
|-
|-
| β<sup>−</sup>, fission ({{val|0.02|(1)|u=%}})
| β<sup>−</sup>t ({{val|0.02|(1)|u=%}})
| {{SimpleNuclide|Beryllium|11}}, {{SimpleNuclide|Hydrogen|3}}
| {{SimpleNuclide|Beryllium|11}}
|-
|-
| β<sup>−</sup>α (< {{val|0.004|u=%}})
| β<sup>−</sup>α (< {{val|0.004|u=%}})
| {{SimpleNuclide|Lithium|10}}
| {{SimpleNuclide|Lithium|10}}
|-id=Beryllium-14m
|-
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|14|m}}
| style="text-indent:1em" | {{SimpleNuclide|Beryllium|14|m}}
| colspan="3" style="text-indent:2em" | {{val|1520|(150)|u=keV}}
| colspan="3" style="text-indent:2em" | {{val|1520|(150)|u=keV}}
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| (2+)
| (2+)
|
|
|-id=Beryllium-15
|
|-
| {{SimpleNuclide|Beryllium|15}}
| {{SimpleNuclide|Beryllium|15}}
|4
|4
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| (5/2+)
| (5/2+)
|
|
|-id=Beryllium-16
|
|-
| {{SimpleNuclide|Beryllium|16}}
| {{SimpleNuclide|Beryllium|16}}
|4
|4
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|{{SimpleNuclide|Beryllium|14}}
|{{SimpleNuclide|Beryllium|14}}
| 0+
| 0+
|
|
|
{{Isotopes table/footer}}
{{Isotopes table/footer}}

==Beryllium-7==
Beryllium-7 is an isotope with a half-life of 53.3 days that is generated naturally as a cosmogenic nuclide.<ref name="7Be-Mishra"/> The rate at which the short-lived {{SimpleNuclide|Beryllium|7}} is transferred from the air to the ground is controlled in part by the weather. {{SimpleNuclide|Beryllium|7}} decay in the Sun is one of the sources of [[solar neutrino]]s, and the first type ever detected using the [[Homestake experiment]]. Presence of {{SimpleNuclide|Beryllium|7}} in sediments is often used to establish that they are fresh, i.e. less than about 3–4 months in age, or about two half-lives of {{SimpleNuclide|Beryllium|7}}.<ref name="yamamoto">{{cite journal |last1=Yamamoto |first1=Masayoshi |last2=Sakaguchi |first2=Aya |last3=Sasaki |first3=Keiichi |last4=Hirose |first4=Katsumi |last5=Igarashi |first5=Yasuhito |last6=Kim |first6=Chang Kyu |title=Seasonal and spatial variation of atmospheric 210Pb and 7Be deposition: features of the Japan Sea side of Japan |journal=Journal of Environmental Radioactivity |date=January 2006 |volume=86 |issue=1 |pages=110–131 |doi=10.1016/j.jenvrad.2005.08.001|pmid=16181712 }}</ref>

⚫
[[File:Be7fromcosmicrays.png|center|thumb|500px|The rate of delivery of {{SimpleNuclide|Beryllium|7}} from the air to the ground in Japan<ref name="yamamoto"/>]]

==Beryllium-10==
⚫
{{main|Beryllium-10}}

[[Image:Solar Activity Proxies.png|thumb|right|upright=1|Plot showing variations in solar activity, including variation in <sup>10</sup>Be concentration which varies inversely with solar activity. (Note that the beryllium scale is inverted, so increases on this scale indicate lower beryllium-10 levels).]]

Beryllium-10 has a half-life of {{val|1.39e6|u=y}}, and decays by [[beta decay]] to stable [[boron-10]] with a maximum energy of 556.2 keV.<ref name="Korschinek">{{cite journal|author1=G. Korschinek|author2=A. Bergmaier|author3=T. Faestermann|author4=U. C. Gerstmann|journal=Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms| volume=268|issue=2| year=2010| pages=187–191|title=A new value for the half-life of <sup>10</sup>Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting|doi=10.1016/j.nimb.2009.09.020|bibcode=2010NIMPB.268..187K}}</ref><ref name="Chmeleff">{{cite journal|author1=J. Chmeleff|author2=F. von Blanckenburg|author3=K. Kossert|author4=D. Jakob|journal=Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms| volume=268|issue=2| year=2010| pages=192–199|title=Determination of the <sup>10</sup>Be half-life by multicollector ICP-MS and liquid scintillation counting| doi=10.1016/j.nimb.2009.09.012|bibcode=2010NIMPB.268..192C|url=http://gfzpublic.gfz-potsdam.de/pubman/item/escidoc:239521}}</ref> It is formed in the Earth's atmosphere mainly by [[cosmic ray spallation]] of nitrogen and oxygen.<ref name="Kov10">{{cite journal|author1=G.A. Kovaltsov|author2=I.G. Usoskin|journal=Earth Planet. Sci. Lett.| volume=291|issue=1–4| year=2010| pages=182–199|title=A new 3D numerical model of cosmogenic nuclide <sup>10</sup>Be production in the atmosphere|doi=10.1016/j.epsl.2010.01.011|bibcode=2010E&PSL.291..182K}}</ref><ref name="Beer12">{{cite book|author1=J. Beer|author2=K. McCracken|author3 = R. von Steiger|year=2012|publisher = Physics of Earth and Space Environments, Springer, Berlin |title=Cosmogenic radionuclides: theory and applications in the terrestrial and space environments| volume= 26| doi=10.1007/978-3-642-14651-0|series=Physics of Earth and Space Environments|isbn=978-3-642-14650-3|s2cid=55739885}}</ref><ref name="Pol16">{{cite journal|author1=S.V. Poluianov|author2=G.A. Kovaltsov|author3=A.L. Mishev|author4=I.G. Usoskin|journal=J. Geophys. Res. Atmos.| volume=121|issue=13| year=2016| pages=8125–8136|title= Production of cosmogenic isotopes <sup>7</sup>Be, <sup>10</sup>Be, <sup>14</sup>C, <sup>22</sup>Na, and <sup>36</sup>Cl in the atmosphere: Altitudinal profiles of yield functions|doi=10.1002/2016JD025034|arxiv=1606.05899|bibcode=2016JGRD..121.8125P|s2cid=119301845}}</ref> <sup>10</sup>Be and its daughter product have been used to examine [[soil erosion]], [[soil formation]] from [[regolith]], the development of [[laterite|lateritic soils]] and the age of [[ice core]]s.<ref name="BalcoShuster2009">{{cite journal|last1= Balco|first1= Greg|last2= Shuster|first2= David L.|year= 2009|title= <sup>26</sup>Al-<sup>10</sup>Be–<sup>21</sup>Ne burial dating|journal= [[Earth and Planetary Science Letters]]|volume= 286|issue= 3–4|pages= 570–575|doi= 10.1016/j.epsl.2009.07.025|url= http://www.bgc.org/shuster/BalcoShuster(2009b)_Al_Be_Ne_burial_dating.pdf|bibcode= 2009E&PSL.286..570B|access-date= 2012-12-10|archive-date= 2015-09-23|archive-url= https://web.archive.org/web/20150923184215/http://www.bgc.org/shuster/BalcoShuster(2009b)_Al_Be_Ne_burial_dating.pdf|url-status= dead}}</ref> <sup>10</sup>Be is a significant isotope used as a [[proxy data]] measure for cosmogenic nuclides to characterize solar and extra-solar attributes of the past from terrestrial samples.<ref name="Paleari">{{cite journal | last = Paleari | first = Chiara I. | author2 = F. Mekhaldi |author3 = F. Adolphi |author4 = M. Christl |author5 = C. Vockenhuber |author6 = P. Gautschi |author7 = J. Beer |author8 = N. Brehm |author9 = T. Erhardt |author10 = H.-A. Synal |author11 = L. Wacker |author12 = F. Wilhelms |author13 = R. Muscheler | title = Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP | journal = Nat. Commun. | volume = 13 | issue = 214 | date = 2022 | page = 214 | doi = 10.1038/s41467-021-27891-4 | pmid = 35017519 | pmc = 8752676 | bibcode = 2022NatCo..13..214P |doi-access = free }}</ref>


==Decay chains==
==Decay chains==
Most isotopes of beryllium within the proton/neutron [[nuclear drip line|drip&nbsp;line]]s decay via [[beta decay]] and/or a combination of beta decay and [[alpha decay]] or neutron emission. However, <sup>7</sup>Be decays only via [[electron capture]], a phenomenon to which its unusually long half-life may be attributed. Also anomalous is <sup>8</sup>Be, which decays via alpha decay to <sup>4</sup>He. This alpha decay is often considered fission, which would be able to account for its extremely short half-life.
Most isotopes of beryllium within the proton/neutron [[nuclear drip line|drip&nbsp;line]]s decay via [[beta decay]] and/or a combination of beta decay and [[alpha decay]] or neutron emission. However, {{SimpleNuclide|Beryllium|7}} decays only via [[electron capture]], a phenomenon to which its unusually long half-life may be attributed. Notably, its half-life can be artificially lowered by 0.83% via [[Endohedral fullerene|endohedral]] enclosure (<sup>7</sup>Be@C<sub>60</sub>).<ref>{{cite journal |last1=Ohtsuki |first1=T. |last2=Yuki |first2=H. |last3=Muto |first3=M. |last4=Kasagi |first4=J. |last5=Ohno |first5=K. |title=Enhanced Electron-Capture Decay Rate of 7Be Encapsulated in C60 Cages |journal=Physical Review Letters |date=9 September 2004 |volume=93 |issue=11 |pages=112501 |doi=10.1103/PhysRevLett.93.112501 |pmid=15447332 |bibcode=2004PhRvL..93k2501O |url=https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.93.112501 |access-date=23 February 2022}}</ref> Also anomalous is {{SimpleNuclide|Beryllium|8}}, which decays via alpha decay to {{SimpleNuclide|Helium|4}}. This alpha decay is often considered fission, which would be able to account for its extremely short half-life.
:<math chem>\begin{array}{l}{}\\
:<math chem>\begin{array}{l}{}\\
\ce{^5_4Be -> [\ce{Unknown}] {^4_3Li} + {^1_1H}} \\
\ce{^5_4Be -> [\ce{Unknown}] {^4_3Li} + {^1_1H}} \\
\ce{^6_4Be -> [5 \ \ce{zs}] {^4_2He} + {2^1_1H}} \\
\ce{^6_4Be -> [5 \ \ce{zs}] {^4_2He} + {2^1_1H}} \\
\ce{{^7_4Be} + e^- -> [53.22 \ \ce{d}] {^7_3Li}} \\
\ce{{^7_4Be} + e^- -> [53.22 \ \ce{d}] {^7_3Li}} \\
\ce{^8_4Be -> [67 \ \ce{as}] {2^4_2He}} \\
\ce{^8_4Be -> [81.9 \ \ce{as}] {2^4_2He}} \\
\ce{^{10}_4Be -> [1.39 \ \ce{Ma}] {^{10}_5B} + e^-} \\
\ce{^{10}_4Be -> [1.387 \ \ce{Ma}] {^{10}_5B} + e^-} \\
\ce{^{11}_4Be -> [13.81 \ \ce{s}] {^{11}_5B} + e^-} \\
\ce{^{11}_4Be -> [13.76 \ \ce{s}] {^{11}_5B} + e^-} \\
\ce{^{11}_4Be -> [13.81 \ \ce{s}] {^7_3Li} + {^4_2He} + e^-} \\
\ce{^{11}_4Be -> [13.76 \ \ce{s}] {^7_3Li} + {^4_2He} + e^-} \\
\ce{^{12}_4Be -> [21.49 \ \ce{ms}] {^{12}_5B} + e^-} \\
\ce{^{12}_4Be -> [21.46 \ \ce{ms}] {^{12}_5B} + e^-} \\
\ce{^{12}_4Be -> [21.49 \ \ce{ms}] {^{11}_5B} + {^1_0n} + e^-} \\
\ce{^{12}_4Be -> [21.46 \ \ce{ms}] {^{11}_5B} + {^1_0n} + e^-} \\
\ce{^{13}_4Be -> [2.7 \ \ce{zs}] {^{12}_4Be} + {^1_0n}} \\
\ce{^{13}_4Be -> [1 \ \ce{zs}] {^{12}_4Be} + {^1_0n}} \\
\ce{^{14}_4Be -> [4.84 \ \ce{ms}] {^{13}_5B} + {^1_0n} + e^-} \\
\ce{^{14}_4Be -> [4.53 \ \ce{ms}] {^{13}_5B} + {^1_0n} + e^-} \\
\ce{^{14}_4Be -> [4.84 \ \ce{ms}] {^{14}_5B} + e^-} \\
\ce{^{14}_4Be -> [4.53 \ \ce{ms}] {^{14}_5B} + e^-} \\
\ce{^{14}_4Be -> [4.84 \ \ce{ms}] {^{12}_5B} + {2^1_0n} + e^-} \\
\ce{^{14}_4Be -> [4.53 \ \ce{ms}] {^{12}_5B} + {2^1_0n} + e^-} \\
\ce{^{15}_4Be -> [790 \ \ce{ys}] {^{14}_4Be} + {^1_0n}} \\{}
\ce{^{15}_4Be -> [790 \ \ce{ys}] {^{14}_4Be} + {^1_0n}} \\{}
\ce{^{16}_4Be -> [650 \ \ce{ys}] {^{14}_4Be} + {2^1_0n}} \\{}
\ce{^{16}_4Be -> [650 \ \ce{ys}] {^{14}_4Be} + {2^1_0n}} \\{}

Latest revision as of 23:06, 9 October 2024

Isotopes of beryllium (4Be)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
7Be trace 53.22 d ε 7Li
8Be synth 81.9 as α 4He
9Be 100% stable
10Be trace 1.387×106 y β− 10B
Standard atomic weight Ar°(Be)

Beryllium (4Be) has 11 known isotopes and 3 known isomers, but only one of these isotopes (9
Be
) is stable and a primordial nuclide. As such, beryllium is considered a monoisotopic element. It is also a mononuclidic element, because its other isotopes have such short half-lives that none are primordial and their abundance is very low (standard atomic weight is 9.0121831(5)). Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons. There are 25 other monoisotopic elements but all have odd atomic numbers, and even numbers of neutrons.

Of the 10 radioisotopes of beryllium, the most stable are 10
Be
 with a half-life of 1.387(12) million years[nb 1] and 7
Be
 with a half-life of 53.22(6) d. All other radioisotopes have half-lives under 15 s, most under 30 milliseconds. The least stable isotope is 16
Be
, with a half-life of 650(130) yoctoseconds.

The 1:1 neutron–proton ratio seen in stable isotopes of many light elements (up to oxygen, and in elements with even atomic number up to calcium) is prevented in beryllium by the extreme instability of 8
Be
 toward alpha decay, which is favored due to the extremely tight binding of 4
He
 nuclei. The half-life for the decay of 8
Be
 is only 81.9(3.7) attoseconds.

Beryllium is prevented from having a stable isotope with 4 protons and 6 neutrons by the very lopsided neutron–proton ratio for such a light element. Nevertheless, this isotope, 10
Be
, has a half-life of 1.387(12) million years,[nb 1] which indicates unusual stability for a light isotope with such a large neutron/proton imbalance. Other possible beryllium isotopes have even more severe mismatches in neutron and proton number, and thus are even less stable.

Most 9
Be
 in the universe is thought to be formed by cosmic ray nucleosynthesis from cosmic ray spallation in the period between the Big Bang and the formation of the Solar System. The isotopes 7
Be
, with a half-life of 53.22(6) d, and 10
Be
 are both cosmogenic nuclides because they are made on a recent timescale in the Solar System by spallation,[4] like 14
C
.

List of isotopes

[edit]
Nuclide
[n 1] 		Z N Isotopic mass (Da)[5]
[n 2][n 3] 		Half-life[1]

[resonance width] 		Decay
mode[1]
[n 4] 		Daughter
isotope
[n 5] 		Spin and
parity[1]
[n 6] 		Isotopic
abundance
Excitation energy
5
Be
[n 7] 		4 1 5.03987(215)# p ?[n 8] 4
Li
 ? 		(1/2+)#
6
Be
 		4 2 6.019726(6) 5.0(3) zs
[91.6(5.6) keV] 		2p 4
He
 		0+
7
Be
[n 9] 		4 3 7.01692871(8) 53.22(6) d ε 7
Li
 		3/2− Trace[n 10]
8
Be
[n 11] 		4 4 8.00530510(4) 81.9(3.7) as
[5.58(25) eV] 		α[n 12] 4
He
 		0+
8m
Be
 		16626(3) keV α 4
He
 		2+
9
Be
 		4 5 9.01218306(8) Stable 3/2− 1
9m
Be
 		14390.3(1.7) keV 1.25(10) as
[367(30) eV] 		3/2−
10
Be
 		4 6 10.01353469(9) 1.387(12)×106 y[nb 1] β− 10
B
 		0+ Trace[n 10]
11
Be
[n 13] 		4 7 11.02166108(26) 13.76(7) s β− (96.7(1)%) 11
B
 		1/2+
β−α (3.3(1)%) 7
Li
β−p (0.0013(3)%) 10
Be
11m
Be
 		21158(20) keV 0.93(13) zs
[500(75) keV] 		IT ?[n 8] 11
Be
 ? 		3/2−
12
Be
 		4 8 12.0269221(20) 21.46(5) ms β− (99.50(3)%) 12
B
 		0+
β−n (0.50(3)%) 11
B
12m
Be
 		2251(1) keV 233(7) ns IT 12
Be
 		0+
13
Be
 		4 9 13.036135(11) 1.0(7) zs n ?[n 8] 12
Be
 ? 		(1/2−)
13m
Be
 		1500(50) keV (5/2+)
14
Be
[n 14] 		4 10 14.04289(14) 4.53(27) ms β−n (86(6)%) 13
B
 		0+
β− (> 9.0(6.3)%) 14
B
β−2n (5(2)%) 12
B
β−t (0.02(1)%) 11
Be
β−α (< 0.004%) 10
Li
14m
Be
 		1520(150) keV (2+)
15
Be
 		4 11 15.05349(18) 790(270) ys n 14
Be
 		(5/2+)
16
Be
 		4 12 16.06167(18) 650(130) ys
[0.73(18) MeV] 		2n 14
Be
 		0+
This table header & footer:
  1. ^ mBe – 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. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  5. ^ Bold symbol as daughter – Daughter product is stable.
  6. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ^ This isotope has not yet been observed; given data is inferred or estimated from periodic trends.
  8. ^ a b c Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
  9. ^ Produced in Big Bang nucleosynthesis, but not primordial, as it all quickly decayed to 7Li
  10. ^ a b cosmogenic nuclide
  11. ^ Intermediate product of triple alpha process in stellar nucleosynthesis as part of the path producing 12C
  12. ^ Also often considered spontaneous fission, as 8
    Be
     splits into two equal 4
    He
     nuclei
  13. ^ Has 1 halo neutron
  14. ^ Has 4 halo neutrons

Beryllium-7

[edit]

Beryllium-7 is an isotope with a half-life of 53.3 days that is generated naturally as a cosmogenic nuclide.[4] The rate at which the short-lived 7
Be
 is transferred from the air to the ground is controlled in part by the weather. 7
Be
 decay in the Sun is one of the sources of solar neutrinos, and the first type ever detected using the Homestake experiment. Presence of 7
Be
 in sediments is often used to establish that they are fresh, i.e. less than about 3–4 months in age, or about two half-lives of 7
Be
.[6]

The rate of delivery of 7
Be
 from the air to the ground in Japan[6]

Beryllium-10

[edit]
Main article: Beryllium-10
Plot showing variations in solar activity, including variation in 10Be concentration which varies inversely with solar activity. (Note that the beryllium scale is inverted, so increases on this scale indicate lower beryllium-10 levels).

Beryllium-10 has a half-life of 1.39×106 y, and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV.[7][8] It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen.[9][10][11] 10Be and its daughter product have been used to examine soil erosion, soil formation from regolith, the development of lateritic soils and the age of ice cores.[12] 10Be is a significant isotope used as a proxy data measure for cosmogenic nuclides to characterize solar and extra-solar attributes of the past from terrestrial samples.[13]

Decay chains

[edit]

Most isotopes of beryllium within the proton/neutron drip lines decay via beta decay and/or a combination of beta decay and alpha decay or neutron emission. However, 7
Be
 decays only via electron capture, a phenomenon to which its unusually long half-life may be attributed. Notably, its half-life can be artificially lowered by 0.83% via endohedral enclosure (7Be@C60).[14] Also anomalous is 8
Be
, which decays via alpha decay to 4
He
. This alpha decay is often considered fission, which would be able to account for its extremely short half-life.

Notes

[edit]
  1. ^ a b c Note that NUBASE2020 uses the tropical year to convert between years and other units of time, not the Gregorian year. The relationship between years and other time units in NUBASE2020 is as follows: 1 y = 365.2422 d = 31 556 926 s

References

[edit]
  1. ^ a b c d 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: Beryllium". CIAAW. 2013.
  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. ^ a b Mishra, Ritesh Kumar; Marhas, Kuljeet Kaur (2019-03-25). "Meteoritic evidence of a late superflare as source of 7 Be in the early Solar System". Nature Astronomy. 3 (6): 498–505. Bibcode:2019NatAs...3..498M. doi:10.1038/s41550-019-0716-0. ISSN 2397-3366. S2CID 126552874.
  5. ^ 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.
  6. ^ a b Yamamoto, Masayoshi; Sakaguchi, Aya; Sasaki, Keiichi; Hirose, Katsumi; Igarashi, Yasuhito; Kim, Chang Kyu (January 2006). "Seasonal and spatial variation of atmospheric 210Pb and 7Be deposition: features of the Japan Sea side of Japan". Journal of Environmental Radioactivity. 86 (1): 110–131. doi:10.1016/j.jenvrad.2005.08.001. PMID 16181712.
  7. ^ G. Korschinek; A. Bergmaier; T. Faestermann; U. C. Gerstmann (2010). "A new value for the half-life of 10Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting". Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 268 (2): 187–191. Bibcode:2010NIMPB.268..187K. doi:10.1016/j.nimb.2009.09.020.
  8. ^ J. Chmeleff; F. von Blanckenburg; K. Kossert; D. Jakob (2010). "Determination of the 10Be half-life by multicollector ICP-MS and liquid scintillation counting". Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 268 (2): 192–199. Bibcode:2010NIMPB.268..192C. doi:10.1016/j.nimb.2009.09.012.
  9. ^ G.A. Kovaltsov; I.G. Usoskin (2010). "A new 3D numerical model of cosmogenic nuclide 10Be production in the atmosphere". Earth Planet. Sci. Lett. 291 (1–4): 182–199. Bibcode:2010E&PSL.291..182K. doi:10.1016/j.epsl.2010.01.011.
  10. ^ J. Beer; K. McCracken; R. von Steiger (2012). Cosmogenic radionuclides: theory and applications in the terrestrial and space environments. Physics of Earth and Space Environments. Vol. 26. Physics of Earth and Space Environments, Springer, Berlin. doi:10.1007/978-3-642-14651-0. ISBN 978-3-642-14650-3. S2CID 55739885.
  11. ^ S.V. Poluianov; G.A. Kovaltsov; A.L. Mishev; I.G. Usoskin (2016). "Production of cosmogenic isotopes 7Be, 10Be, 14C, 22Na, and 36Cl in the atmosphere: Altitudinal profiles of yield functions". J. Geophys. Res. Atmos. 121 (13): 8125–8136. arXiv:1606.05899. Bibcode:2016JGRD..121.8125P. doi:10.1002/2016JD025034. S2CID 119301845.
  12. ^ Balco, Greg; Shuster, David L. (2009). "26Al-10Be–21Ne burial dating" (PDF). Earth and Planetary Science Letters. 286 (3–4): 570–575. Bibcode:2009E&PSL.286..570B. doi:10.1016/j.epsl.2009.07.025. Archived from the original (PDF) on 2015-09-23. Retrieved 2012-12-10.
  13. ^ Paleari, Chiara I.; F. Mekhaldi; F. Adolphi; M. Christl; C. Vockenhuber; P. Gautschi; J. Beer; N. Brehm; T. Erhardt; H.-A. Synal; L. Wacker; F. Wilhelms; R. Muscheler (2022). "Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP". Nat. Commun. 13 (214): 214. Bibcode:2022NatCo..13..214P. doi:10.1038/s41467-021-27891-4. PMC 8752676. PMID 35017519.
  14. ^ Ohtsuki, T.; Yuki, H.; Muto, M.; Kasagi, J.; Ohno, K. (9 September 2004). "Enhanced Electron-Capture Decay Rate of 7Be Encapsulated in C60 Cages". Physical Review Letters. 93 (11): 112501. Bibcode:2004PhRvL..93k2501O. doi:10.1103/PhysRevLett.93.112501. PMID 15447332. Retrieved 23 February 2022.
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