Calcium-44

Properties and data of the isotope ⁴⁴Ca.

Contents

General data

Name of the isotope:Calcium-44; Ca-44Symbol:⁴⁴Ca or 4420CaMass number A:44 (= number of nucleons)Atomic number Z:20 (= number of protons)Neutrons N:24Isotopic mass:43.955482(2) u (atomic weight of Calcium-44)Nuclide mass:43.9445106 u (calculated nuclear mass without electrons)Mass excess:-41.46825 MeVMass defect:0.408976624 u (per nucleus)Nuclear binding energy:380.9592714 MeV (per nucleus)
8.65816526 MeV (average binding energy per nucleon)Separation energy:S_N = 11.13117(23) MeV (first neutron)
S_P = 12.1823(5) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:3.5179(21) femtometer fmMirror nucleus:Chromium-44Year of discovery:1922

Parent Nuclides

Direct parent isotopes are: ⁴⁴K, ⁴⁴Sc.

Occurrence

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

	Atomic Mass m_a	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 a	7/2-
Isotope ⁴²Ca	41.958618(1) u	0.647(23) %	stable	0+
Isotope ⁴³Ca	42.958766(2) u	0.135(10) %	stable	7/2-
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 a	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 24) and isobaric (same nucleon number A = 44) with Calcium-44. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 24	Isobar A = 44
10	³⁴Ne
11	³⁵Na
12	³⁶Mg
13	³⁷Al
14	³⁸Si	⁴⁴Si
15	³⁹P	⁴⁴P
16	⁴⁰S	⁴⁴S
17	⁴¹Cl	⁴⁴Cl
18	⁴²Ar	⁴⁴Ar
19	⁴³K	⁴⁴K
20	⁴⁴Ca	⁴⁴Ca
21	⁴⁵Sc	⁴⁴Sc
22	⁴⁶Ti	⁴⁴Ti
23	⁴⁷V	⁴⁴V
24	⁴⁸Cr	⁴⁴Cr
25	⁴⁹Mn	⁴⁴Mn
26	⁵⁰Fe
27	⁵¹Co
28	⁵²Ni
29	⁵³Cu
30	⁵⁴Zn