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Isotopes of Calcium

List, data and properties of all known isotopes of Calcium as well as radioactive decay products and intermediate products.

 

Calcium isotopes

Naturally occurring calcium is a cocktail of 7 different isotopes, 6 of which are stable and one is extremely long-lived (>100,000 years). At almost 97%, the isotope calcium-40 makes up the largest proportion:

 

Naturally Occurring Calcium Isotopes

Atomic Mass maQuantityHalf-lifeSpin
Calcium
Isotopic mixture
40,078 u100 %
Isotope 40Ca39,9625909(2) u96,941(156) %stable0+
Isotope 41Ca40,96227792(15) utraces9.94(15) × 104 a7/2-
Isotope 42Ca41,958618(1) u0,647(23) %stable0+
Isotope 43Ca42,958766(2) u0,135(10) %stable7/2-
Isotope 44Ca43,955482(2) u2,086(110) %stable0+
Isotope 46Ca45,95369(2) u0,004(3) %stable0+
Isotope 48Ca47,9525228(8) u0,187(21) %1.9 × 1019 a0+

 

Due to variations in the isotopic composition of natural calcium, the mean atomic mass (standard atomic mass) may vary.

On the basis of theoretical considerations, it is assumed that the calcium isotopes 40 and 46 have extremely long half-lives of not less than 5.9 × 1021 (40approx ) and 100 × 1015 (46Ca) years a β+β+-decay to 40< /sup>Ar or 46Ti are subject; there are no corresponding confirmations yet.

The quasi-stable calcium isotope 41 is formed by neutron activation from 40Ca.

 

Isotope Table: Calcium

 

Atomic Properties

Isotope
Nuclide
ZANNameAtomic Mass
[Nuclear Mass]
{Mass Excess}
Spin I
(h/2π)
μParent
123456789
34Ca203414Calcium-3434.01487(32) u
[34.0038986 u]
{13.85132 MeV}
0+
35Ca203515Calcium-3535.00514(21) u
[34.9941686 u]
{4.78788 MeV}
(1/2+)
36Ca203616Calcium-3635.99307(4) u
[35.9820986 u]
{-6.45525 MeV}
0+38Ti
37Ca203717Calcium-3736.9858979(7) u
[36.9749265 u]
{-13.13602 MeV}
(3/2+)38Sc
38Ca203818Calcium-3837.97631923(21) u
[37.9653478 u]
{-22.0585 MeV}
0+39Sc
39Ti
39Ca203919Calcium-3938.9707108(6) u
[38.9597394 u]
{-27.28271 MeV}
3/2+1.02140(16)40Ti
40Ca204020Calcium-4039.9625909(2) u
[39.9516195 u]
{-34.84635 MeV}
0+40K
40Sc
41Ti
41Ca204121Calcium-4140.96227792(15) u
[40.9513065 u]
{-35.13789 MeV}
7/2--1.59443(7)41Sc
42Ca204222Calcium-4241.958618(1) u
[41.9476466 u]
{-38.54708 MeV}
0+42K
42Sc
43Ca204323Calcium-4342.958766(2) u
[42.9477946 u]
{-38.40922 MeV}
7/2--1.31733(6)43K
43Sc
44Ca204424Calcium-4443.955482(2) u
[43.9445106 u]
{-41.46825 MeV}
0+44K
44Sc
45Ca204525Calcium-4544.9561863(4) u
[44.9452149 u]
{-40.8122 MeV}
7/2-- 1.3264(13)45K
46Ca204626Calcium-4645.95369(2) u
[45.9427186 u]
{-43.13749 MeV}
0+46K
47Ca204727Calcium-4746.9545414(24) u
[46.94357 u]
{-42.34441 MeV}
7/2--1.4064(11)47K
48K
48Ca204828Calcium-4847.9525228(8) u
[47.9415514 u]
{-44.22473 MeV}
0+48K
49K
49Ca204929Calcium-4948.95562288(22) u
[48.9446515 u]
{-41.33702 MeV}
3/2--1.3799(8)49K
50K
50Ca205030Calcium-5049.9574992(17) u
[49.9465278 u]
{-39.58924 MeV}
0+50K
51K
51Ca205131Calcium-5150.9609957(6) u
[50.9500243 u]
{-36.33227 MeV}
3/2(-)-1.0496(11)51K
52K
52Ca205232Calcium-5251.9632136(7) u
[51.9522422 u]
{-34.26631 MeV}
0+52K
53K
53Ca205333Calcium-5352.96845(5) u
[52.9574786 u]
{-29.38864 MeV}
(1/2-)54K
54Ca205434Calcium-5453.97299(5) u
[53.9620186 u]
{-25.15965 MeV}
0+
55Ca205535Calcium-5554.98030(32) u
[54.9693286 u]
{-18.35043 MeV}
(5/2-)
56Ca205636Calcium-5655.98508(43) u
[55.9741086 u]
{-13.89789 MeV}
0+
57Ca205737Calcium-5756.99262(43) u
[56.9816486 u]
{-6.87443 MeV}
5/2-
58Ca205838Calcium-5857.99794(54) u
[57.9869686 u]
{-1.91888 MeV}
0+

 

Radioactive Decay Properties

IsotopeRadioactive DecayAEExtern
Half-lifeDecay ModeProbabilityEnergy
1101112131415
Ca-3435 nsp → 33K
2p ?
?

AL
Ca-3525.7(2) msβ+35K
β+, p → 34Ar
β+, 2p → 33Cl
< 0.1 %
95.9(14) %
4.1(6) %
15.770 MeV
15.690 MeV
11.027 MeV
AL
Ca-36101.2(20) msβ+36K
EC, p → 35Ar
48.8 %
51.2(10) %
10.987 MeV
9.319 MeV
AL
Ca-37181.1(10) msβ+37K
EC, p → 36Ar
17.9 %
82.1 %
11.638 MeV
9.781 MeV
AL
Ca-38443.76 (35) msβ+38K100 %6.74226(27) MeVAL
Ca-39860.3(10) msβ+39K100 %6.5245(6) MeVAL
Ca-40stableAL
Ca-419.94(15) × 104 aEC → 41K100 %0.42165(14) MeVAL
Ca-42stableAL
Ca-43stableAL
Ca-44stableAL
Ca-45162.61(9) dβ-45Sc100 %0.2597(7) MeVAL
Ca-46stableAL
Ca-474.536(3) dβ-47Sc100 %1.9922(12) MeVAL
Ca-481.9 × 1019 aβ-48Sc
-48Ti
25 %
75 %
0.2793 MeV
4.272 MeV
AL
Ca-498.718(6) minβ-49Sc100 %5.2615(27) MeVAL
Ca-5013.45(5) sβ-50Sc100 %4.958(15) MeVAL
Ca-5110.0(8) sβ-51Sc
β-, n → 50Sc
99.9 %
0.1 %
6.896(20) MeV
0.144(15) MeV
AL
Ca-524.6(3) sβ-52Sc
β-, n → 51Sc
> 98 %
< 2 %
6.18(8) MeV
0.891(20)
AL
Ca-53461(90) msβ-53Sc
β-, n → 52Sc
60 %
40(10) %
9.52(10) MeV
2.98(9) MeV
AL
Ca-54107(14) msβ-54Sc
β-, n → 53Sc
β-, 2n → 52Sc
100 %
?
?
8.73(28) MeV
5.67(11) MeV
AL
Ca-5522(2) msβ-55Sc
β-, n → 54Sc
100 %
?
11.81(54) MeV
7.47(40) MeV
AL
Ca-5611(2) msβ-56Sc
β-, n → 55Sc
?
?
10.95(71) MeV
8.19(60) MeV
AL
Ca-57620 nsβ-57Sc
β-, n → 56Sc
β-, 2n → 55Sc
?
?
?
14.12(136) MeV
9.91(71) MeV
AL
Ca-58620 nsβ-58Sc
β-, n → 57Sc
?
?
12.96(64) MeV
11.01(140) MeV
AL

 

Notes (related to the columns):

1 - nuclide, isotope symbol.
2 - Z = number of protons (atomic number).
3 - Mass number A.
4 - N = number of neutrons.
5 - Identification of the Calcium isotope.
6 - Relative atomic mass of the Calcium isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
7 - Nuclear spin I, unit: h/2π.
8 - Nuclear magnetic moment μmag.
9 - Source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
10 - Decay: Half-live of the Calcium isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
11 - Decay: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
12 - Decay percentage in percent (%).
13 - Decay energy; Particle energy related to decay type.
14 - AE = Excitation energy for metastable nuclei.
15 - Other information and notes: AL = Adopted Levels (link to external data [1]).

Miscellaneous:

()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
  - unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.

 

NMR active Calcium nuclides

Nuclide
quantity 1)
spin
Nuclear magnetic
moment
μ/μN
Gyromagnetic
ratio
107 rad T-1 s-1
Quadrupole
moment
Q fm-2
Resonant
frequency
v0 bei 1 T
Relative
sensitivity
H0 = const.
v0 = const. 2)
43Ca
0,135(10) %
7/2-
-1,31733(6)- 1,8025- 4,08(8)2,86970,00643
1,4154

1) Quantity Percentage of natural occurrence.

2) Related to 1H = 1,000.

 

Radiation Protection

According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Calcium radionuclides:

NuclideLimit ValueHASS limitSCDaughter NuclidesHalf-life
Ca-41107 Bq100 Bq/gUnbegrenzt (UL)100000 a
Ca-45+107 Bq1004 Bq/g100 TBq100 Bq/cm2163.0 d
Ca-47+106 Bq10 Bq/g0,06 TBq1 Bq/cm24.5 d

(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)

 

Literature Sources and References

Properties of the Calcium nucleides

[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.

[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.

[3] - Live Chart of Nuclides. Nuclear structure and decay data.

Calcium: NMR properties - 43Ca-NMR

[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.

[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.

[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.

[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).

More sources:

[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.

[9] - S. Amos, J. L.Gross, M. Thoennessen:
Discovery of the calcium, indium, tin, and platinum isotopes.
In: Atomic Data and Nuclear Data Tables, (2011), DOI 10.1016/j.adt.2011.03.001.

[10] - NN:
Bindungsenergien exotischer Calcium-Kerne.
In: Internetchemie News, (2013), DOI https://www.internetchemie.info/news/2013/jun13/bindungsenergien-exotischer-calcium-kerne.php.

[11] - NN:
Ladungsradien protonenreicher Calcium-Isotope vermessen.
In: Internetchemie News, (2019), DOI https://www.internetchemie.info/news/2019/feb19/ladungsradien_protonenreicher_calcium-isotope.php.

 


Category: Isotopes

Last update: 05.07.2020



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