Periodic Table/Magnesium/²¹Mg

← 20Mg22Mg →

²¹Mg

Magnesium-21

Radioactive· Half-life: 120 ms

Nuclear Propertiesbinding energy · spin-parity · abundance

Protons (Z)

12

Neutrons (N)

9

Mass Number (A)

21

Atomic Mass

21.011706AMU

Spin / Parity

5/2+

Binding E/A

6.813keV

Natural Abundance

Trace / None

Half-life

120 ms

Decay Modesoverview · half-life · α · β⁻ · β⁺

β⁺

100.0%

β⁺p

20.1%

β⁺α

0.1%

B+pA

0.0%

Decay Chain

²¹MgMagnesium120 ms

β⁺100.0%

β⁺p²⁰Ne20.1%

β⁺α¹⁷F0.12%

B+pA¹⁶O0.02%

²¹NaSodium22.5 s

β⁺100.0%

²¹NeNeonSTABLE

3-step decay chain → stable · Primary path shown · branching ratios indicated

Other Isotopes of Magnesium

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

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