Potassium-43

Properties and data of the isotope ⁴³K.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Potassium-43 is a radioisotope of the chemical element potassium, which has 24 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 43.

The discovery of the radioactive isotope was announced in 1949 [1]; according to this, potassium-43 could be produced and identified by irradiating argon-40 with alpha particles (helium-4 nuclei):

⁴⁰Ar(α,p)⁴³K.

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

General data

Name of the isotope:Potassium-43; K-43Symbol:⁴³K or 4319KMass number A:43 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:24Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.2631578947368 (= neutron-proton ratio)Neutron excess (N-Z):5Isotopic mass:42.9607347(4) u (atomic weight of Potassium-43)Nuclide mass:42.9503119 u (calculated nuclear mass without electrons)Mass excess:-36.57539 MeVMass defect:0.395898892 u (per nucleus)Nuclear binding energy:368.7774425 MeV (per nucleus)
8.57621959 MeV (average binding energy per nucleon)Separation energy:S_N = 9.6247(4) MeV (first neutron)
S_P = 9.442(6) MeV (first proton)Half-life:22.3(1) hDecay constant λ:8.634120335823 × 10^-6 s^-1Specific activity α:1.237997353904 × 10⁺¹⁷ Bq g^-1
3345938.7943357 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = +0.1633(8)Nuclear g-factor:g_l = 0.10886666666667Charge radius:3.4556(86) femtometer fmMirror nucleus:Chromium-43Year of discovery:1949

Radioactive Decay

Half-life T_½ = 22.3(1) h (hours) respectively 8.0280 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴³Ca	100 %	1.8335(5) MeV

Parent Nuclides

Direct parent isotope is: ⁴³Ar.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^43mK	738.30(6) keV	200(5) ns	7/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 24) and isobaric (same nucleon number A = 43) with Potassium-43. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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

External data and identifiers

Adopted Levels, Gammas:NuDat 43K

Literature and References

[1] - Roy Overstreet, Louis Jacobson, P. R. Stout:
Evidence for a New Isotope of Potassium.
In: Physical Review, 75, 231, (1949), DOI 10.1103/PhysRev.75.231.