Potassium-41

Properties and data of the isotope ⁴¹K.

Contents

General data

Name of the isotope:Potassium-41; K-41Symbol:⁴¹K or 4119KMass number A:41 (= number of nucleons)Atomic number Z:19 (= number of protons)Neutrons N:22Isotopic mass:40.96182526(3) u (atomic weight of Potassium-41)Nuclide mass:40.9514024 u (calculated nuclear mass without electrons)Mass excess:-35.55954 MeVMass defect:0.3774785 u (per nucleus)Nuclear binding energy:351.61895788 MeV (per nucleus)
8.57607214 MeV (average binding energy per nucleon)Separation energy:S_N = 10.09537(6) MeV (first neutron)
S_P = 7.80862(0) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = +0.214872(5)Charge radius:3.4518(55) femtometer fmMirror nucleus:Titanium-41Year of discovery:1921

Parent Nuclides

Direct parent isotopes are: ⁴¹Ca, ⁴¹Ar.

Occurrence

Comparison of the natural Potassium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Potassium Isotopic mixture	39.0983 u	100 %
Isotope ³⁹K	38.96370649(3) u	93.2581(44) %	stable	3/2+
Isotope ⁴¹K	40.96182526(3) u	6.7302(44) %	stable	3/2+
Isotope ⁴⁰K	39.9639982(4) u	0.0117(1) %	1.248(3) × 10⁹ a	4-

NMR data

Nuclear magnetic properties of the NMR active Nuclide ⁴¹K

Isotope:⁴¹K-NMRQuantity:6.7302(44) %Spin:3/2+Nuclearmagnetic moment
μ/μ_N:+0.214872(5)Gyromagnetic ratio γ:0.686 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = 0.143248Quadrupole moment Q:+ 0.0734(7) barn (100 fm²)Resonance frequency:v₀ = 1.0919 at 1 TRelative Sensitivity:0.00008 (H₀ = const.)
0.1282 (v₀ = const.)
[related to ¹H = 1.000]

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 22) and isobaric (same nucleon number A = 41) with Potassium-41. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 22	Isobar A = 41
9	³¹F
10	³²Ne
11	³³Na
12	³⁴Mg
13	³⁵Al	⁴¹Al
14	³⁶Si	⁴¹Si
15	³⁷P	⁴¹P
16	³⁸S	⁴¹S
17	³⁹Cl	⁴¹Cl
18	⁴⁰Ar	⁴¹Ar
19	⁴¹K	⁴¹K
20	⁴²Ca	⁴¹Ca
21	⁴³Sc	⁴¹Sc
22	⁴⁴Ti	⁴¹Ti
23	⁴⁵V	⁴¹V
24	⁴⁶Cr	⁴¹Cr
25	⁴⁷Mn
26	⁴⁸Fe
27	⁴⁹Co
28	⁵⁰Ni