Zirconium-91

Properties and data of the isotope ⁹¹Zr.

Contents

General data

Name of the isotope:Zirconium-91; Zr-91Symbol:⁹¹Zr or 9140ZrMass number A:91 (= number of nucleons)Atomic number Z:40 (= number of protons)Neutrons N:51Isotopic mass:90.90564(2) u (atomic weight of Zirconium-91)Nuclide mass:90.8836978 u (calculated nuclear mass without electrons)Mass excess:-87.89577 MeVMass defect:0.849271996 u (per nucleus)Nuclear binding energy:791.09176864 MeV (per nucleus)
8.69331614 MeV (average binding energy per nucleon)Separation energy:S_N = 8.19435(15) MeV (first neutron)
S_P = 8.6905(16) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = - 1.3022(4)Charge radius:4.2845(13) femtometer fmYear of discovery:1934

Parent Nuclides

Direct parent isotopes are: ⁹¹Nb, ⁹¹Y.

Occurrence

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

	Atomic Mass m_a	Quantity	Half-life	Spin
Zirconium Isotopic mixture	91.224 u	100 %
Isotope ⁹⁰Zr	89.90470(2) u	51.45(4) %	stable	0+
Isotope ⁹¹Zr	90.90564(2) u	11.22(5) %	stable	5/2+
Isotope ⁹²Zr	91.90503(2) u	17.15(3) %	stable	0+
Isotope ⁹⁴Zr	93.90631(2) u	17.38(4) %	stable	0+
Isotope ⁹⁶Zr	95.90827(2) u	2.80(2) %	2.0(4) × 10¹⁹ a	0+

NMR data

Nuclear magnetic properties of the NMR active Nuclide ⁹¹Zr

Isotope:⁹¹Zr-NMRQuantity:11.22(5) %Spin:5/2+Nuclearmagnetic moment
μ/μ_N:- 1.3022(4)Gyromagnetic ratio γ:2.4975 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = -0.52088Quadrupole moment Q:- 0.176(3) barn (100 fm²)Resonance frequency:v₀ = 3.9748 at 1 TRelative Sensitivity:0.00949 (H₀ = const.)
1.0892 (v₀ = const.)
[related to ¹H = 1.000]

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
^91mZr	3167.3(4) keV	4.35(14) μs	(21/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 51) and isobaric (same nucleon number A = 91) with Zirconium-91. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 51	Isobar A = 91
28	⁷⁹Ni
29	⁸⁰Cu
30	⁸¹Zn
31	⁸²Ga
32	⁸³Ge
33	⁸⁴As	⁹¹As
34	⁸⁵Se	⁹¹Se
35	⁸⁶Br	⁹¹Br
36	⁸⁷Kr	⁹¹Kr
37	⁸⁸Rb	⁹¹Rb
38	⁸⁹Sr	⁹¹Sr
39	⁹⁰Y	⁹¹Y
40	⁹¹Zr	⁹¹Zr
41	⁹²Nb	⁹¹Nb
42	⁹³Mo	⁹¹Mo
43	⁹⁴Tc	⁹¹Tc
44	⁹⁵Ru	⁹¹Ru
45	⁹⁶Rh	⁹¹Rh
46	⁹⁷Pd	⁹¹Pd
47	⁹⁸Ag
48	⁹⁹Cd
49	¹⁰⁰In
50	¹⁰¹Sn