Zirconium-90

Properties and data of the isotope ⁹⁰Zr.

Contents

General data

Name of the isotope:Zirconium-90; Zr-90Symbol:⁹⁰Zr or 9040ZrMass number A:90 (= number of nucleons)Atomic number Z:40 (= number of protons)Neutrons N:50Isotopic mass:89.90470(2) u (atomic weight of Zirconium-90)Nuclide mass:89.8827578 u (calculated nuclear mass without electrons)Mass excess:-88.77138 MeVMass defect:0.84154707999998 u (per nucleus)Nuclear binding energy:783.89605574 MeV (per nucleus)
8.70995617 MeV (average binding energy per nucleon)Separation energy:S_N = 11.9659(28) MeV (first neutron)
S_P = 8.3503(4) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:4.2694(10) femtometer fmYear of discovery:1924

Parent Nuclides

Direct parent isotopes are: ⁹⁰Nb, ⁹⁰Y.

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+

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
^90m1Zr	2319.00(1) keV	809.2(20) ms	5-
^90m2Zr	3589.419(16) keV	131(4) ns	8+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 50) and isobaric (same nucleon number A = 90) with Zirconium-90. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 50	Isobar A = 90
28	⁷⁸Ni
29	⁷⁹Cu
30	⁸⁰Zn
31	⁸¹Ga
32	⁸²Ge	⁹⁰Ge
33	⁸³As	⁹⁰As
34	⁸⁴Se	⁹⁰Se
35	⁸⁵Br	⁹⁰Br
36	⁸⁶Kr	⁹⁰Kr
37	⁸⁷Rb	⁹⁰Rb
38	⁸⁸Sr	⁹⁰Sr
39	⁸⁹Y	⁹⁰Y
40	⁹⁰Zr	⁹⁰Zr
41	⁹¹Nb	⁹⁰Nb
42	⁹²Mo	⁹⁰Mo
43	⁹³Tc	⁹⁰Tc
44	⁹⁴Ru	⁹⁰Ru
45	⁹⁵Rh	⁹⁰Rh
46	⁹⁶Pd	⁹⁰Pd
47	⁹⁷Ag
48	⁹⁸Cd
49	⁹⁹In
50	¹⁰⁰Sn