Calcium-43 is a stable, naturally occurring isotope of the chemical element calcium, which has 23 neutrons in its atomic nucleus in addition to the element-specific 20 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 43.
Ca-43 was first described and characterized using mass spectrometric and photometric analyses in 1934 [1].
See also: List of individual Calcium isotopes (and general data sources).
General data
Name of the isotope:Calcium-43; Ca-43Symbol:43Ca or 4320CaMass number A:43 (= number of nucleons)Atomic number Z:20 (= number of protons)Neutrons N:23Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.15 (= neutron-proton ratio)Neutron excess (N-Z):3Isotopic mass:42.95876638(24) u (atomic weight of Calcium-43)Nuclide mass:42.947795 u (calculated nuclear mass without electrons)Mass excess:-38.40887 MeVMass defect:0.397027328 u (per nucleus)Nuclear binding energy:369.82857387 MeV (per nucleus) 8.60066451 MeV (average binding energy per nucleon)Separation energy:SN = 7.93290(17) MeV (first neutron) SP = 10.67581(25) MeV (first proton)Half-life:stableSpin and parity: (nuclear angular momentum)7/2-Magnetic dipole moment:μ(μN) = -1.31733(6)Charge radius:3.4954(19) femtometer fmMirror nucleus:Vanadium-43Year of discovery:1934
Comparison of the natural Calcium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
Atomic Mass ma
Quantity
Half-life
Spin
Calcium Isotopic mixture
40.078 u
100 %
Isotope 40Ca
39.9625909(2) u
96.941(156) %
stable
0+
Isotope 41Ca
40.96227792(15) u
[trace]
9.94(15) × 104 years
7/2-
Isotope 42Ca
41.958618(1) u
0.647(23) %
stable
0+
Isotope 44Ca
43.955482(2) u
2.086(110) %
stable
0+
Isotope 46Ca
45.95369(2) u
0.004(3) %
stable
0+
Isotope 48Ca
47.952522654(19) u
0.187(21) %
5.3 × 1019 years
0+
Isotope 43Ca
42.95876638(24) u
0.135(10) %
stable
7/2-
NMR data
Nuclear magnetic properties and parameters of the NMR active Nuclide43Ca
Isotope:43Ca-NMRQuantity:0.135(10) %Spin:7/2-Nuclearmagnetic moment μ/μN:-1.31733(6)Gyromagnetic ratio γ:0 · 107 rad T-1 s-1 0.00000 MHz T-1Nuclear g-factor:gl = -0.37638Quadrupole moment Q:- 0.0408(8) barn (100 fm2)Resonance frequency:v0 = 2.8697 MHz at 1 TRelative Sensitivity:[related to 1H = 1.000]: 0.00643 (H0 = const.) 1.4154 (v0 = const.) 0.00000868 (at natural abundance) relative receptivity as compared to 13C: 0.0510 (at natural abundance)Reference compound: (conditions)0.1 M calcium dichloride solution CaClâ‚‚ in deuterium oxide D2OFrequency ratio:Ξ(43Ca) = 6.730029 % [based on the reference substance]
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 23) and isobaric (same nucleon number A = 43) with Calcium-43. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
