Krypton-90

Properties and data of the isotope ⁹⁰Kr.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

See also: List of individual Krypton isotopes (and general data sources).

General data

Name of the isotope:Krypton-90; Kr-90Symbol:⁹⁰Kr or 9036KrMass number A:90 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:54Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.5 (= neutron-proton ratio)Neutron excess (N-Z):18Isotopic mass:89.9195279(20) u (atomic weight of Krypton-90)Nuclide mass:89.8997798 u (calculated nuclear mass without electrons)Mass excess:-74.95928 MeVMass defect:0.83007871599999 u (per nucleus)Nuclear binding energy:773.21334348 MeV (per nucleus)
8.59125937 MeV (average binding energy per nucleon)Separation energy:S_N = 6.4948(28) MeV (first neutron)
S_P = 13.974(4) MeV (first proton)Half-life:32.32(9) sDecay constant λ:0.021446385537127 s^-1Specific activity α:1.451159040911 × 10⁺²⁰ Bq g^-1
3922051461.9219 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.2423(69) femtometer fmYear of discovery:1951

Radioactive Decay

Half-life T_½ = 32.32(9) s respectively 3.232 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁹⁰Rb	100 %	4.406(7) MeV

Parent Nuclides

Direct parent isotopes are: ⁹⁰Br, ⁹¹Br.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 54) and isobaric (same nucleon number A = 90) with Krypton-90. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 54	Isobar A = 90
30	⁸⁴Zn
31	⁸⁵Ga
32	⁸⁶Ge	⁹⁰Ge
33	⁸⁷As	⁹⁰As
34	⁸⁸Se	⁹⁰Se
35	⁸⁹Br	⁹⁰Br
36	⁹⁰Kr	⁹⁰Kr
37	⁹¹Rb	⁹⁰Rb
38	⁹²Sr	⁹⁰Sr
39	⁹³Y	⁹⁰Y
40	⁹⁴Zr	⁹⁰Zr
41	⁹⁵Nb	⁹⁰Nb
42	⁹⁶Mo	⁹⁰Mo
43	⁹⁷Tc	⁹⁰Tc
44	⁹⁸Ru	⁹⁰Ru
45	⁹⁹Rh	⁹⁰Rh
46	¹⁰⁰Pd	⁹⁰Pd
47	¹⁰¹Ag
48	¹⁰²Cd
49	¹⁰³In
50	¹⁰⁴Sn
51	¹⁰⁵Sb
52	¹⁰⁶Te