Isotopes of magnesium#Magnesium-21

Magnesium (₁₂Mg) 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 sodium while the heavier isotopes decay to isotopes of 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 ⁴⁰Mg in 2019 showed the unexpected difference in its nuclear structure, compared to the lighter neighboring isotopes.{{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}}{{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}}

File:Magnesium chart.png

List of isotopes

{{Isotopes table

| symbol = Mg

| refs = NUBASE2020, AME2020 II

| notes = mass#, unc(), var[], hl#, daughter-st, spin#, spin(), p, n

}}

|-id=Magnesium-18

| {{chem|18|Mg}}{{cite journal |doi=10.1103/PhysRevLett.127.262502 |title=First observation of the four-proton unbound nucleus ¹⁸Mg |last=Jin |first=Y. |display-authors=et al. |journal=Physical Review Letters |volume=127 |number=262502 |date=2021|page=262502 |pmid=35029460 |osti=1837749 |s2cid=245434485 }}

| style="text-align:right" | 12

| style="text-align:right" | 6

| {{val|4.0|(3.4)|u=zs}}

| 2p

| {{chem|16|Ne}}

| 0+

|-id=Magnesium-19

| {{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}}

| 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}}

| β⁺ ({{val|69.7|(1.2)|u=%}})

| {{chem|20|Na}}

| rowspan=2|0+

| rowspan=2|

| β⁺p ({{val|30.3|(1.2)|u=%}})

| {{chem|19|Ne}}

| rowspan=4|{{chem|21|Mg}} {{Anchor|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⁺ ({{val|79.8|(2.1)|u=%}})

| {{chem|21|Na}}

| rowspan=4|5/2+

| rowspan=4|

| β⁺p ({{val|20.1|(2.1)|u=%}})

| {{chem|20|Ne}}

| β⁺α ({{val|0.116|(18)|u=%}})

| {{chem|17|F}}

| β⁺pα ({{val|0.016|(3)|u=%}})

| {{chem|16|O}}

| {{chem|22|Mg}} {{Anchor|Magnesium-22}}

| style="text-align:right" | 12

| style="text-align:right" | 10

| {{val|21.99957060|(17)}}

| {{val|3.8745|(7)|u=s}}

| β⁺

| {{chem|22|Na}}

| 0+

| {{chem|23|Mg}} {{Anchor|Magnesium-23}}

| style="text-align:right" | 12

| style="text-align:right" | 11

| {{val|22.99412377|(3)}}

| {{val|11.3039|(32)|u=s}}

| β⁺

| {{chem|23|Na}}

| 3/2+

| {{chem|24|Mg}} {{Anchor|Magnesium-24}}

| style="text-align:right" | 12

| {{val|23.985041689|(14)}}

| colspan=3 align=center|Stable

| 0+

| colspan=2 align=center|[{{val|0.7888}}, {{val|0.7905}}]

| {{chem|25|Mg}} {{Anchor|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}}, {{val|0.10034}}]

| {{chem|26|Mg}}Used in radiodating events early in the Solar System's history {{Anchor|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}}, {{val|0.1109}}]

| {{chem|27|Mg}} {{Anchor|Magnesium-27}}

| style="text-align:right" | 12

| style="text-align:right" | 15

| {{val|26.98434065|(5)}}

| {{val|9.435|(27)|u=min}}

| β⁻

| {{chem|27|Al}}

| 1/2+

| {{chem|28|Mg}} {{Anchor|Magnesium-28}}

| style="text-align:right" | 12

| style="text-align:right" | 16

| {{val|27.98387543|(28)}}

| {{val|20.915|(9)|u=h}}

| β⁻

| {{chem|28|Al}}

| 0+

| {{chem|29|Mg}} {{Anchor|Magnesium-29}}

| style="text-align:right" | 12

| style="text-align:right" | 17

| {{val|28.9886072|(4)}}

| {{val|1.30|(12)|u=s}}

| β⁻

| {{chem|29|Al}}

| 3/2+

| rowspan=2|{{chem|30|Mg}} {{Anchor|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⁻ (> {{val|99.94|u=%}})

| {{chem|30|Al}}

| rowspan=2|0+

| rowspan=2|

| β⁻n (< {{val|0.06|u=%}})

| {{chem|29|Al}}

| rowspan=2|{{chem|31|Mg}} {{Anchor|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⁻ ({{val|93.8|(1.9)|u=%}})

| {{chem|31|Al}}

| rowspan=2|1/2+

| rowspan=2|

| β⁻n ({{val|6.2|(1.9)|u=%}})

| {{chem|30|Al}}

| rowspan=2|{{chem|32|Mg}} {{Anchor|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⁻ ({{val|94.5|(5)|u=%}})

| {{chem|32|Al}}

| rowspan=2|0+

| rowspan=2|

| β⁻n ({{val|5.5|(5)|u=%}})

| {{chem|31|Al}}

| rowspan=3|{{chem|33|Mg}} {{Anchor|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⁻ ({{val|86|(2)|u=%}})

| {{chem|33|Al}}

| rowspan=3|3/2−

| rowspan=3|

| β⁻n ({{val|14|(2)|u=%}})

| {{chem|32|Al}}

| β⁻2n ?Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.

| {{chem|31|Al}} ?

| rowspan=3|{{chem|34|Mg}} {{Anchor|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⁻ (> {{val|78.9|(7.0)|u=%}})

| {{chem|34|Al}}

| rowspan=3|0+

| rowspan=3|

| β⁻n ({{val|21|(7)|u=%}})

| {{chem|33|Al}}

| β⁻2n (< {{val|0.1|u=%}})

| {{chem|32|Al}}

| rowspan=3|{{chem|35|Mg}} {{Anchor|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⁻n ({{val|52|(46)|u=%}})

| {{chem|34|Al}}

| rowspan=3|(3/2−, 5/2−)

| rowspan=3|

| β⁻ ({{val|48|(46)|u=%}})

| {{chem|35|Al}}

| β⁻2n ?

| {{chem|33|Al}} ?

| rowspan=3|{{chem|36|Mg}} {{Anchor|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⁻ ({{val|52|(12)|u=%}})

| {{chem|36|Al}}

| rowspan=3|0+

| rowspan=3|

| β⁻n ({{val|48|(12)|u=%}})

| {{chem|35|Al}}

| β⁻2n ?

| {{chem|34|Al}} ?

| rowspan=3|{{chem|37|Mg}} {{Anchor|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⁻ ?

| {{chem|37|Al}} ?

| rowspan=3|(3/2−)

| rowspan=3|

| β⁻n ?

| {{chem|36|Al}} ?

| β⁻2n ?

| {{chem|35|Al}} ?

| rowspan=3|{{chem|38|Mg}} {{Anchor|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 (stat), 2 (sys)) ms{{cite journal |last1=Crawford |first1=H. L. |last2=Tripathi |first2=V. |last3=Allmond |first3=J. M. |display-authors=et al. |title=Crossing N {{=}} 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 }}

| β⁻n (81%)

| {{chem|37|Al}}

| rowspan=3|0+

| rowspan=3|

| β⁻ (9%)

| {{chem|38|Al}}

| β⁻2n (9%)

| {{chem|36|Al}}

| rowspan=3|{{chem|40|Mg}} {{Anchor|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# ms [> {{val|170|u=ns}}]

| β⁻ ?

| {{chem|40|Al}} ?

| rowspan=3|0+

| rowspan=3|

| β⁻n ?

| {{chem|39|Al}} ?

| β⁻2n ?

| {{chem|38|Al}} ?

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

Category:Magnesium

Magnesium