Potassium-45 is a radioisotope of the chemical element potassium, which has 26 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 45. The short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of 45K is exclusively for academic purposes.
The radioactive nuclide was discovered during the irradiation of enriched calcium-48 samples (94%) with 52 MeV alpha particles (helium-4 nuclei) [1].
See also: List of individual Potassium isotopes (and general data sources).
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:26Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3684210526316 (= neutron-proton ratio)Neutron excess (N-Z):7Isotopic 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:SN = 8.9055(7) MeV (first neutron) SP = 11.2314(17) MeV (first proton)Half-life:17.81(61) minDecay constant λ:0.00064864980400519 s-1Specific activity α:8.688168027099 × 10+18 Bq g-1 234815352.08376 Ci g-1Spin and parity: (nuclear angular momentum)3/2+Magnetic dipole moment:μ(μN) = + 0.1734(8)Nuclear g-factor:gl = 0.1156Charge radius:3.4605(118) femtometer fmMirror nucleus:Iron-45Year of discovery:1964
Radioactive Decay
Half-life T½ = 17.81(61) min (minutes) respectively 1.0686 × 103 seconds s.
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.
