Potassium-36

Properties and data of the isotope ³⁶K.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Potassium-36 is a radioisotope of the chemical element potassium, which has 17 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 36.

The discovery of the radioactive isotope upon irradiation of enriched argon-36 gas with protons of an energy of 23 MeV and the charge exchange reaction initiated by this was reported in 1967 [1]:

³⁶Ar(p,n)³⁶K.

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

General data

Name of the isotope:Potassium-36; K-36Symbol:³⁶K or 3619KMass number A:36 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:17Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):0.89473684210526 (= neutron-proton ratio)Neutron excess (N-Z):-2Isotopic mass:35.9813019(3) u (atomic weight of Potassium-36)Nuclide mass:35.9708791 u (calculated nuclear mass without electrons)Mass excess:-17.41717 MeVMass defect:0.31467728000001 u (per nucleus)Nuclear binding energy:293.11999826 MeV (per nucleus)
8.14222217 MeV (average binding energy per nucleon)Separation energy:S_N = 14.3156(6) MeV (first neutron)
S_P = 1.6589(8) MeV (first proton)Half-life:341(3) msDecay constant λ:2.0326896790614 s^-1Specific activity α:3.497469591956 × 10⁺²² Bq g^-1
945262051880.11 Ci g^-1Spin and parity:
(nuclear angular momentum)2+Magnetic dipole moment:μ(μ_N) = (+) 0.548(1)Mirror nucleus:Chlorine-36Year of discovery:1967

Radioactive Decay

Half-life T_½ = 341(3) ms respectively 3.41 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy
EC/β⁺	³⁶Ar	99.95 %	12.8144(3) MeV
EC, p	³⁵Cl	0.048(14) %	4.298 MeV
EC, α	³²S	0.0034(13) %	6,165 MeV

Parent Nuclides

Direct parent isotope is: ³⁶Ca.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 17) and isobaric (same nucleon number A = 36) with Potassium-36. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 17	Isobar A = 36
7	²⁴N
8	²⁵O
9	²⁶F
10	²⁷Ne
11	²⁸Na	³⁶Na
12	²⁹Mg	³⁶Mg
13	³⁰Al	³⁶Al
14	³¹Si	³⁶Si
15	³²P	³⁶P
16	³³S	³⁶S
17	³⁴Cl	³⁶Cl
18	³⁵Ar	³⁶Ar
19	³⁶K	³⁶K
20	³⁷Ca	³⁶Ca
21	³⁸Sc	³⁶Sc
22	³⁹Ti
23	⁴⁰V
24	⁴¹Cr
25	⁴²Mn

External data and identifiers

Adopted Levels, Gammas:NuDat 36K

Literature and References

[1] - R. E. Berg, J. L. Snelgrove, E. Kashy:
³⁶K Decay and T = 1 Analog in ³⁶Ar.
In: Physical Review, 153, 1165, (1967), DOI 10.1103/PhysRev.153.1165.