View source for Physics:Isotopes of magnesium

{{Short description|Nuclides with atomic number of 12 but with different mass numbers}}
{{infobox magnesium isotopes}}
[[Chemistry:Magnesium|Magnesium]] (<sub>12</sub>Mg) naturally occurs in three stable isotopes: {{chem|24|Mg}}, {{chem|25|Mg}}, and {{chem|26|Mg}}. There are 19 radioisotopes that have been discovered, ranging from {{chem|18|Mg}} to {{chem|40|Mg}} (with the exception of {{chem|39|Mg}}). The longest-lived radioisotope is {{chem|28|Mg}} with a half-life of {{val|20.915|(9)|u=hours}}. The lighter isotopes mostly decay to isotopes of [[Chemistry:Sodium|sodium]] while the heavier isotopes decay to isotopes of [[Chemistry:Aluminium|aluminium]]. The shortest-lived is proton-unbound {{chem|18|Mg}} with a half-life of {{val|4.0|(3.4)|u=zeptoseconds}}.

A precise measurement of the neutron-rich <sup>40</sup>Mg in 2019 showed the unexpected difference in its  nuclear structure, compared to the lighter neighboring isotopes.<ref>{{Cite web |last=glennroberts |date=2019-02-07 |title=New Measurements of Exotic Magnesium Suggest Surprising Shape-Shift |url=https://newscenter.lbl.gov/2019/02/07/new-measurements-exotic-magnesium-suggest-surprising-shape-shift/ |access-date=2023-09-10 |website=Berkeley Lab News Center |language=en-US}}</ref><ref>{{Cite web |date=2019-08-01 |title=NP A Change in Structure for a S... {{!}} U.S. DOE Office of Science(SC) |url=https://science.osti.gov/np/Highlights/2019/NP-2019-08-a |access-date=2023-09-10 |website=science.osti.gov |language=en-US}}</ref> 

[[File:Magnesium chart.png|thumb|The abundances of the naturally occurring isotopes of magnesium.]]

== List of isotopes ==
{{Isotopes table
| symbol = Mg
| refs = NUBASE2020, AME2020 II
| notes = mass#, unc(), var[], hl#, daughter-st, spin#, spin(), p, n
}}
|-
| {{chem|18|Mg}}<ref name=18Mg>{{cite journal |doi=10.1103/PhysRevLett.127.262502 |title=First observation of the four-proton unbound nucleus <sup>18</sup>Mg |last=Jin |first=Y. |display-authors=et al. |journal=[[Physics:Physical Review Letters|Physical Review Letters]] |volume=127 <!-- |issue=26 --> |number=262502 |date=2021|page=262502 |pmid=35029460 |osti=1837749 |s2cid=245434485 }}</ref>
| style="text-align:right" | 12
| style="text-align:right" | 6
| 
| {{val|4.0|(3.4)|u=zs}}
| 2p
| {{chem|16|Ne}}
| 0+
|
|
|-
| {{chem|19|Mg}}
| style="text-align:right" | 12
| style="text-align:right" | 7
| {{val|19.034180|(60)}}
| {{val|5|(3)|u=ps}}
| 2p
| {{chem|17|Ne}}
| 1/2−#
|
|
|-
| rowspan=2|{{chem|20|Mg}} {{Anchor|Magnesium-20}} <!-- linked from redirect [[Physics:Magnesium-20|Magnesium-20]] -->
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 8
| rowspan=2|{{val|20.0187631|(20)}}
| rowspan=2|{{val|90.4|(5)|u=ms}}
| [[Physics:Beta decay|β<sup>+</sup>]] ({{val|69.7|(1.2)|u=%}})
| {{chem|20|Na}}
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| [[Physics:Proton emission|β<sup>+</sup>p]] ({{val|30.3|(1.2)|u=%}})
| {{chem|19|Ne}}
|-
| rowspan=4|{{chem|21|Mg}} {{Anchor|Magnesium-21}} <!-- linked from redirect [[Physics:Magnesium-21|Magnesium-21]] -->
| rowspan=4 style="text-align:right" | 12
| rowspan=4 style="text-align:right" | 9
| rowspan=4|{{val|21.0117058|(8)}}
| rowspan=4|{{val|120.0|(4)|u=ms}}
| β<sup>+</sup> ({{val|79.8|(2.1)|u=%}})
| {{chem|21|Na}}
| rowspan=4|5/2+
| rowspan=4|
| rowspan=4|
|-
| β<sup>+</sup>p ({{val|20.1|(2.1)|u=%}})
| '''{{chem|20|Ne}}'''
|- 
| [[Physics:Alpha decay|β<sup>+</sup>α]] ({{val|0.116|(18)|u=%}})
| {{chem|17|F}}
|-
| β<sup>+</sup>pα ({{val|0.016|(3)|u=%}})
| '''{{chem|16|O}}'''
|-
| {{chem|22|Mg}} {{Anchor|Magnesium-22}} <!-- linked from redirect [[Physics:Magnesium-22|Magnesium-22]] -->
| style="text-align:right" | 12
| style="text-align:right" | 10
| {{val|21.99957060|(17)}}
| {{val|3.8745|(7)|u=s}}
| β<sup>+</sup>
| {{chem|22|Na}}
| 0+
|
|
|-
| {{chem|23|Mg}} {{Anchor|Magnesium-23}} <!-- linked from redirect [[Physics:Magnesium-23|Magnesium-23]] -->
| style="text-align:right" | 12
| style="text-align:right" | 11
| {{val|22.99412377|(3)}}
| {{val|11.3039|(32)|u=s}}
| β<sup>+</sup>
| '''{{chem|23|Na}}'''
| 3/2+
|
|
|-
| {{chem|24|Mg}} {{Anchor|Magnesium-24}} <!-- linked from redirect [[Physics:Magnesium-24|Magnesium-24]] -->
| style="text-align:right" | 12
| style="text-align:right" | 12
| {{val|23.985041689|(14)}}
| colspan=3 align=center|'''Stable'''
| 0+
| colspan=2 align=center|[{{val|0.7888}},&nbsp;{{val|0.7905}}]
|-
| {{chem|25|Mg}} {{Anchor|Magnesium-25}} <!-- linked from redirect [[Physics:Magnesium-25|Magnesium-25]] -->
| style="text-align:right" | 12
| style="text-align:right" | 13
| {{val|24.98583697|(5)}}
| colspan=3 align=center|'''Stable'''
| 5/2+
| colspan=2 align=center|[{{val|0.09988}},&nbsp;{{val|0.10034}}]
|-
| {{chem|26|Mg}}<ref group="n">Used in radiodating events early in the Solar System's history</ref> {{Anchor|Magnesium-26}} <!-- linked from redirect [[Physics:Magnesium-26|Magnesium-26]] -->
| style="text-align:right" | 12
| style="text-align:right" | 14
| {{val|25.98259297|(3)}}
| colspan=3 align=center|'''Stable'''
| 0+
| colspan=2 align=center|[{{val|0.1096}},&nbsp;{{val|0.1109}}]
|-
| {{chem|27|Mg}} {{Anchor|Magnesium-27}} <!-- linked from redirect [[Physics:Magnesium-27|Magnesium-27]] -->
| style="text-align:right" | 12
| style="text-align:right" | 15
| {{val|26.98434065|(5)}}
| {{val|9.435|(27)|u=min}}
| β<sup>−</sup>
| '''{{chem|27|Al}}'''
| 1/2+
|
|
|-
| {{chem|28|Mg}} {{Anchor|Magnesium-28}} <!-- linked from redirect [[Physics:Magnesium-28|Magnesium-28]] -->
| style="text-align:right" | 12
| style="text-align:right" | 16
| {{val|27.98387543|(28)}}
| {{val|20.915|(9)|u=h}}
| β<sup>−</sup>
| {{chem|28|Al}}
| 0+
|
|
|-
| {{chem|29|Mg}} {{Anchor|Magnesium-29}} <!-- linked from redirect [[Physics:Magnesium-29|Magnesium-29]] -->
| style="text-align:right" | 12
| style="text-align:right" | 17
| {{val|28.9886072|(4)}}
| {{val|1.30|(12)|u=s}}
| β<sup>−</sup>
| {{chem|29|Al}}
| 3/2+
|
|
|-
| rowspan=2|{{chem|30|Mg}} {{Anchor|Magnesium-30}} <!-- linked from redirect [[Physics:Magnesium-30|Magnesium-30]] -->
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 18
| rowspan=2|{{val|29.9904655|(14)}}
| rowspan=2|{{val|317|(4)|u=ms}}
| β<sup>−</sup> (> {{val|99.94|u=%}})
| {{chem|30|Al}}
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| [[Physics:Neutron emission|β<sup>−</sup>n]] (< {{val|0.06|u=%}})
| {{chem|29|Al}}
|-
| rowspan=2|{{chem|31|Mg}} {{Anchor|Magnesium-31}} <!-- linked from redirect [[Physics:Magnesium-31|Magnesium-31]] -->
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 19
| rowspan=2|{{val|30.996648|(3)}}
| rowspan=2|{{val|270|(2)|u=ms}}
| β<sup>−</sup> ({{val|93.8|(1.9)|u=%}})
| {{chem|31|Al}}
| rowspan=2|1/2+
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup>n ({{val|6.2|(1.9)|u=%}})
| {{chem|30|Al}}
|-
| rowspan=2|{{chem|32|Mg}} {{Anchor|Magnesium-32}} <!-- linked from redirect [[Physics:Magnesium-32|Magnesium-32]] -->
| rowspan=2 style="text-align:right" | 12
| rowspan=2 style="text-align:right" | 20
| rowspan=2|{{val|31.999110|(4)}}
| rowspan=2|{{val|80.4|(4)|u=ms}}
| β<sup>−</sup> ({{val|94.5|(5)|u=%}})
| {{chem|32|Al}}
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup>n ({{val|5.5|(5)|u=%}})
| {{chem|31|Al}}
|-
| rowspan=3|{{chem|33|Mg}} {{Anchor|Magnesium-33}} <!-- linked from redirect [[Physics:Magnesium-33|Magnesium-33]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 21
| rowspan=3|{{val|33.0053279|(29)}}
| rowspan=3|{{val|92.0|(1.2)|u=ms}}
| β<sup>−</sup> ({{val|86|(2)|u=%}})
| {{chem|33|Al}}
| rowspan=3|3/2−
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup>n ({{val|14|(2)|u=%}})
| {{chem|32|Al}}
|-
| β<sup>−</sup>2n ?<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>
| {{chem|31|Al}} ?
|-
| rowspan=3|{{chem|34|Mg}} {{Anchor|Magnesium-34}} <!-- linked from redirect [[Physics:Magnesium-34|Magnesium-34]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 22
| rowspan=3|{{val|34.008935|(7)}}
| rowspan=3|{{val|44.9|(4)|u=ms}}
| β<sup>−</sup> (> {{val|78.9|(7.0)|u=%}})
| {{chem|34|Al}}
| rowspan=3|0+
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup>n ({{val|21|(7)|u=%}})
| {{chem|33|Al}}
|-
| β<sup>−</sup>2n (< {{val|0.1|u=%}})
| {{chem|32|Al}}
|-
| rowspan=3|{{chem|35|Mg}} {{Anchor|Magnesium-35}} <!-- linked from redirect [[Physics:Magnesium-35|Magnesium-35]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 23
| rowspan=3|{{val|35.01679|(29)}}
| rowspan=3|{{val|11.3|(6)|u=ms}}
| β<sup>−</sup>n ({{val|52|(46)|u=%}})
| {{chem|34|Al}}
| rowspan=3|(3/2−,&nbsp;5/2−)
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup> ({{val|48|(46)|u=%}})
| {{chem|35|Al}}
|-
| β<sup>−</sup>2n ?<ref group="n" name="decay mode 1" />
| {{chem|33|Al}} ?
|-
| rowspan=3|{{chem|36|Mg}} {{Anchor|Magnesium-36}} <!-- linked from redirect [[Physics:Magnesium-36|Magnesium-36]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 24
| rowspan=3|{{val|36.02188|(74)}}
| rowspan=3|{{val|3.9|(1.3)|u=ms}}
| β<sup>−</sup> ({{val|52|(12)|u=%}})
| {{chem|36|Al}}
| rowspan=3|0+
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup>n ({{val|48|(12)|u=%}})
| {{chem|35|Al}}
|-
| β<sup>−</sup>2n ?<ref group="n" name="decay mode 1" />
| {{chem|34|Al}} ?
|-
| rowspan=3|{{chem|37|Mg}} {{Anchor|Magnesium-37}} <!-- linked from redirect [[Physics:Magnesium-37|Magnesium-37]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 25
| rowspan=3|{{val|37.03029|(75)}}
| rowspan=3|{{val|8|(4)|u=ms}}
| β<sup>−</sup> ?<ref group="n" name="decay mode 1" />
| {{chem|37|Al}} ?
| rowspan=3|(3/2−)
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup>n ?<ref group="n" name="decay mode 1" />
| {{chem|36|Al}} ?
|-
| β<sup>−</sup>2n ?<ref group="n" name="decay mode 1" />
| {{chem|35|Al}} ?
|-
| rowspan=3|{{chem|38|Mg}} {{Anchor|Magnesium-38}} <!-- linked from redirect [[Physics:Magnesium-38|Magnesium-38]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 26
| rowspan=3|{{val|38.03658|(54)}}#
| rowspan=3|3.1(4&nbsp;(stat), 2&nbsp;(sys))&nbsp;ms<ref name=NR129>{{cite journal |last1=Crawford |first1=H. L. |last2=Tripathi |first2=V. |last3=Allmond |first3=J. M. |display-authors=et al. |title=Crossing ''N''&nbsp;{{=}}&nbsp;28 toward the neutron drip line: first measurement of half-lives at FRIB |date=2022 |journal=Physical Review Letters |volume=129 |number=212501 |page=212501 |doi=10.1103/PhysRevLett.129.212501|pmid=36461950 |bibcode=2022PhRvL.129u2501C |s2cid=253600995 |doi-access=free }}</ref>
| β<sup>−</sup>n (81%)
| {{chem|37|Al}}
| rowspan=3|0+
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup> (9%)
| {{chem|38|Al}}
|-
| β<sup>−</sup>2n (9%)
| {{chem|36|Al}}
|-
| rowspan=3|{{chem|40|Mg}} {{Anchor|Magnesium-40}} <!-- linked from redirect [[Physics:Magnesium-40|Magnesium-40]] -->
| rowspan=3 style="text-align:right" | 12
| rowspan=3 style="text-align:right" | 28
| rowspan=3|{{val|40.05319|(54)}}#
| rowspan=3|1#&nbsp;ms [> {{val|170|u=ns}}]
| β<sup>−</sup> ?<ref group="n" name="decay mode 1" />
| {{chem|40|Al}} ?
| rowspan=3|0+
| rowspan=3|
| rowspan=3|
|-
| β<sup>−</sup>n ?<ref group="n" name="decay mode 1" />
| {{chem|39|Al}} ?
|-
| β<sup>−</sup>2n ?<ref group="n" name="decay mode 1" />
| {{chem|38|Al}} ?
|-
{{Isotopes table/footer}}

==External links==
*[https://web.archive.org/web/20070731013420/http://ie.lbl.gov/education/parent/Mg_iso.htm Magnesium isotopes data from ''The Berkeley Laboratory Isotopes Project's'']

==References==
{{Reflist}}

{{Navbox element isotopes}}

[[Category:Isotopes of magnesium| ]]
[[Category:Magnesium]]
[[Category:Lists of isotopes by element|Magnesium]]

{{Sourceattribution|Isotopes of magnesium}}