Potassium-51

Properties and data of the isotope ⁵¹K.

Content

General data

Name of the isotope:Potassium-51; K-51Symbol:⁵¹K or 5119KMass number A:51 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:32Isotopic mass:50.975828(14) u (atomic weight of Potassium-51)Nuclide mass:50.9654052 u (calculated nuclear mass without electrons)Mass excess:-22.51607 MeVMass defect:0.45012492 u (per nucleus)Nuclear binding energy:419.28866223 MeV (per nucleus)
8.22134632 MeV (average binding energy per nucleon)Separation energy:S_N = 4.860(15) MeV (first neutron)
S_P = 16.47(50) MeV (first proton)Half-life:365(5) msDecay constant λ:1.8990333713971 s^-1Specific activity α:2.287249292054 × 10⁺²² Bq g^-1
618175484339.14 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = +0.513(2)Nuclear g-factor:g_l = 0.342Year of discovery:1983

Radioactive Decay

Half-life T_½ = 365(5) ms respectively 3.65 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁵¹Ca	35(8) %	13.816(13) MeV
β^-, n	⁵⁰Ca	65(8) %	9.002(13) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 32) and isobaric (same nucleon number A = 51) with Potassium-51. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 32	Isobar A = 51
16	⁴⁸S
17	⁴⁹Cl	⁵¹Cl
18	⁵⁰Ar	⁵¹Ar
19	⁵¹K	⁵¹K
20	⁵²Ca	⁵¹Ca
21	⁵³Sc	⁵¹Sc
22	⁵⁴Ti	⁵¹Ti
23	⁵⁵V	⁵¹V
24	⁵⁶Cr	⁵¹Cr
25	⁵⁷Mn	⁵¹Mn
26	⁵⁸Fe	⁵¹Fe
27	⁵⁹Co	⁵¹Co
28	⁶⁰Ni	⁵¹Ni
29	⁶¹Cu
30	⁶²Zn
31	⁶³Ga
32	⁶⁴Ge
33	⁶⁵As
34	⁶⁶Se
35	⁶⁷Br
36	⁶⁸Kr