Magnesium-24

Properties and data of the isotope ²⁴Mg.

Contents

Magnesium-24 is a stable isotope of the chemical element magnesium, which has 12 neutrons in its atomic nucleus in addition to the element-specific 12 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 24. ²⁴Mg is one of the three isotopes that make up the earth's natural magnesium deposits (see below).

In 1920, the physicist Arthur Jeffrey Dempster described the isotopic composition of magnesium for the first time. For his experiments, he used an apparatus for positive ray analysis; the cylindrical anode contained the magnesium and was irradiated with electrons [1].

General data

Name of the isotope:Magnesium-24; Mg-24Symbol:²⁴Mg or 2412MgMass number A:24 (= number of nucleons)Atomic number Z:12 (= number of protons)Neutrons N:12Isotopic mass:23.98504170(9) u (atomic weight of Magnesium-24)Nuclide mass:23.9784588 u (calculated nuclear mass without electrons)Mass excess:-13.93357 MeVMass defect:0.212837676 u (per nucleus)Nuclear binding energy:198.25701817 MeV (per nucleus)
8.26070909 MeV (average binding energy per nucleon)Separation energy:S_N = 16.53122(3) MeV (first neutron)
S_P = 11.692696(13) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:3.0570(16) femtometer fmYear of discovery:1920

Parent Nuclides

Direct parent isotopes are: ²⁵Si, ²⁴Al, ²⁴Na, ²⁶P, ²⁸P.

Occurrence

Comparison of the natural Magnesium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Magnesium Isotopic mixture	24.305 u	100 %
Isotope ²⁴Mg	23.98504170(9) u	78.965(49) % [78.88 - 79.05 %]	stable	0+
Isotope ²⁵Mg	24.9858370(3) u	10.011 % [9.988 - 10.034 %]	stable	5/2+
Isotope ²⁶Mg	25.9825930(2) u	11.024 % [10.96 - 11.09 %]	stable	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 12) and isobaric (same nucleon number A = 24) with Magnesium-24. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 12	Isobar A = 24
4	¹⁶Be
5	¹⁷B
6	¹⁸C
7	¹⁹N	²⁴N
8	²⁰O	²⁴O
9	²¹F	²⁴F
10	²²Ne	²⁴Ne
11	²³Na	²⁴Na
12	²⁴Mg	²⁴Mg
13	²⁵Al	²⁴Al
14	²⁶Si	²⁴Si
15	²⁷P	²⁴P
16	²⁸S
17	²⁹Cl
18	³⁰Ar