Potassium-56

Properties and data of the isotope ⁵⁶K.

Content

General data

Name of the isotope:Potassium-56; K-56Symbol:⁵⁶K or 5619KMass number A:56 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:37Isotopic mass:56.00851(86) u (atomic weight of Potassium-56)Nuclide mass:55.9980872 u (calculated nuclear mass without electrons)Mass excess:7.92701 MeVMass defect:0.4607675 u (per nucleus)Nuclear binding energy:429.20216165 MeV (per nucleus)
7.66432432 MeV (average binding energy per nucleon)Separation energy:S_N = 0.85(106) MeV (first neutron)Half-life:> 620 nsDecay constant λ:1117979.3234838 s^-1Specific activity α:1.202072500146 × 10⁺²⁸ Bq g^-1
3.248844594989 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2009

Radioactive Decay

Half-life T_½ = > 620 ns respectively 6.2 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	⁵⁶Ca	?	21.82(89) MeV
β^-, n	⁵⁵Ca		18.21(85) MeV
β^-, 2n	⁵⁴Ca

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 37) and isobaric (same nucleon number A = 56) with Potassium-56. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 37	Isobar A = 56
19	⁵⁶K	⁵⁶K
20	⁵⁷Ca	⁵⁶Ca
21	⁵⁸Sc	⁵⁶Sc
22	⁵⁹Ti	⁵⁶Ti
23	⁶⁰V	⁵⁶V
24	⁶¹Cr	⁵⁶Cr
25	⁶²Mn	⁵⁶Mn
26	⁶³Fe	⁵⁶Fe
27	⁶⁴Co	⁵⁶Co
28	⁶⁵Ni	⁵⁶Ni
29	⁶⁶Cu	⁵⁶Cu
30	⁶⁷Zn	⁵⁶Zn
31	⁶⁸Ga
32	⁶⁹Ge
33	⁷⁰As
34	⁷¹Se
35	⁷²Br
36	⁷³Kr
37	⁷⁴Rb
38	⁷⁵Sr
39	⁷⁶Y
40	⁷⁷Zr