Potassium-45

Properties and data of the isotope ⁴⁵K.

Content

General data

Name of the isotope:Potassium-45; K-45Symbol:⁴⁵K or 4519KMass number A:45 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:26Isotopic mass:44.9606915(6) u (atomic weight of Potassium-45)Nuclide mass:44.9502687 u (calculated nuclear mass without electrons)Mass excess:-36.61563 MeVMass defect:0.41327192399999 u (per nucleus)Nuclear binding energy:384.96031757 MeV (per nucleus)
8.55467372 MeV (average binding energy per nucleon)Separation energy:S_N = 8.9055(7) MeV (first neutron)
S_P = 11.2313(17) MeV (first proton)Half-life:17.81(61) minDecay constant λ:0.00064864980400519 s^-1Specific activity α:8.877864746567 × 10⁺¹⁸ Bq g^-1
239942290.44776 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = + 0.1734(8)Nuclear g-factor:g_l = 0.1156Charge radius:3.4605(118) femtometer fmMirror nucleus:Iron-45Year of discovery:1964

Radioactive Decay

Half-life T_½ = 17.81(61) min (minutes) respectively 1.0686 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁵Ca	100 %	4.1965(6) MeV

Parent Nuclides

Direct parent isotope is: ⁴⁵Ar.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 26) and isobaric (same nucleon number A = 45) with Potassium-45. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 26	Isobar A = 45
11	³⁷Na
12	³⁸Mg
13	³⁹Al
14	⁴⁰Si
15	⁴¹P	⁴⁵P
16	⁴²S	⁴⁵S
17	⁴³Cl	⁴⁵Cl
18	⁴⁴Ar	⁴⁵Ar
19	⁴⁵K	⁴⁵K
20	⁴⁶Ca	⁴⁵Ca
21	⁴⁷Sc	⁴⁵Sc
22	⁴⁸Ti	⁴⁵Ti
23	⁴⁹V	⁴⁵V
24	⁵⁰Cr	⁴⁵Cr
25	⁵¹Mn	⁴⁵Mn
26	⁵²Fe	⁴⁵Fe
27	⁵³Co
28	⁵⁴Ni
29	⁵⁵Cu
30	⁵⁶Zn