Potassium-44

Properties and data of the isotope ⁴⁴K.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Potassium-44 is a radioisotope of the chemical element potassium, which has 25 neutrons in its atomic nucleus in addition to the element-specific 19 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 44.

The discovery of the radioactive isotope by irradiating calcium-44 with neutrons was reported in 1954 [1]:

⁴⁴Ca(n,p)⁴⁴K.

See also: List of individual Potassium isotopes (and general data sources).

General data

Name of the isotope:Potassium-44; K-44Symbol:⁴⁴K or 4419KMass number A:44 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:25Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.3157894736842 (= neutron-proton ratio)Neutron excess (N-Z):6Isotopic mass:43.9615870(5) u (atomic weight of Potassium-44)Nuclide mass:43.9511642 u (calculated nuclear mass without electrons)Mass excess:-35.78148 MeVMass defect:0.40371150799999 u (per nucleus)Nuclear binding energy:376.05484743 MeV (per nucleus)
8.54670108 MeV (average binding energy per nucleon)Separation energy:S_N = 7.2774(6) MeV (first neutron)
S_P = 11.061(5) MeV (first proton)Half-life:22.13(19) minDecay constant λ:0.00052202679662596 s^-1Specific activity α:7.310974190565 × 10⁺¹⁸ Bq g^-1
197593897.04231 Ci g^-1Spin and parity:
(nuclear angular momentum)2-Magnetic dipole moment:μ(μ_N) = - 0.856(4)Nuclear g-factor:g_l = -0.428Charge radius:3.4563(101) femtometer fmMirror nucleus:Manganese-44Year of discovery:1954

Radioactive Decay

Half-life T_½ = 22.13(19) min (minutes) respectively 1.3278 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁴Ca	100 %	5.6872(5) MeV

Parent Nuclides

Direct parent isotope is: ⁴⁴Ar.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 25) and isobaric (same nucleon number A = 44) with Potassium-44. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 25	Isobar A = 44
11	³⁶Na
12	³⁷Mg
13	³⁸Al
14	³⁹Si	⁴⁴Si
15	⁴⁰P	⁴⁴P
16	⁴¹S	⁴⁴S
17	⁴²Cl	⁴⁴Cl
18	⁴³Ar	⁴⁴Ar
19	⁴⁴K	⁴⁴K
20	⁴⁵Ca	⁴⁴Ca
21	⁴⁶Sc	⁴⁴Sc
22	⁴⁷Ti	⁴⁴Ti
23	⁴⁸V	⁴⁴V
24	⁴⁹Cr	⁴⁴Cr
25	⁵⁰Mn	⁴⁴Mn
26	⁵¹Fe
27	⁵²Co
28	⁵³Ni
29	⁵⁴Cu
30	⁵⁵Zn