Magnesium-24

Main isotopes of magnesium

Iso­tope Decay abun­dance half-life mode energy (MeV) pro­duct 24Mg 79.0% is stable with 12 neutrons 25Mg 10.0% is stable with 13 neutrons 26Mg 11.0% is stable with 14 neutrons
Standard atomic weight (Ar)	[24.304, 24.307] Conventional: 24.305

Magnesium (₁₂Mg) naturally occurs in three stable isotopes, ²⁴Mg, ²⁵Mg, and ²⁶Mg. There are 19 radioisotopes that have been discovered, ranging from ¹⁹Mg to ⁴⁰Mg. The longest-lived radioisotope is ²⁸Mg with a half-life of 20.915 hours. The lighter isotopes mostly decay to isotopes of sodium while the heavier isotopes decay to isotopes of aluminium. The shortest-lived is ³⁹Mg with a half-life shorter than 180 nanoseconds, or possibly ⁴⁰Mg, with a half-life longer than 170 nanoseconds (the half-life of ¹⁹Mg is unknown).

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