Krypton-73

Properties and data of the isotope ⁷³Kr.

Contents

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

General data

Name of the isotope:Krypton-73; Kr-73Symbol:⁷³Kr or 7336KrMass number A:73 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:37Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.0277777777778 (= neutron-proton ratio)Neutron excess (N-Z):1Isotopic mass:72.939289(7) u (atomic weight of Krypton-73)Nuclide mass:72.9195409 u (calculated nuclear mass without electrons)Mass excess:-56.55193 MeVMass defect:0.66301404399999 u (per nucleus)Nuclear binding energy:617.5936039 MeV (per nucleus)
8.46018635 MeV (average binding energy per nucleon)Separation energy:S_N = 10.682(10) MeV (first neutron)
S_P = 4.779(7) MeV (first proton)Half-life:27.3(10) sDecay constant λ:0.025390006613917 s^-1Specific activity α:2.123641614774 × 10⁺²⁰ Bq g^-1
5739571931.8219 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2)-Mirror nucleus:Rubidium-73Year of discovery:1972

Radioactive Decay

Half-life T_½ = 27.3(10) s respectively 2.73 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁷³Br	> 99 %	7.096(10) MeV
EC, p	⁷²Se	0.25(3) %

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
^73mKr	433.55(13) keV	107(10) ns	(9/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 37) and isobaric (same nucleon number A = 73) with Krypton-73. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 37	Isobar A = 73
19	⁵⁶K
20	⁵⁷Ca
21	⁵⁸Sc
22	⁵⁹Ti
23	⁶⁰V
24	⁶¹Cr
25	⁶²Mn
26	⁶³Fe	⁷³Fe
27	⁶⁴Co	⁷³Co
28	⁶⁵Ni	⁷³Ni
29	⁶⁶Cu	⁷³Cu
30	⁶⁷Zn	⁷³Zn
31	⁶⁸Ga	⁷³Ga
32	⁶⁹Ge	⁷³Ge
33	⁷⁰As	⁷³As
34	⁷¹Se	⁷³Se
35	⁷²Br	⁷³Br
36	⁷³Kr	⁷³Kr
37	⁷⁴Rb	⁷³Rb
38	⁷⁵Sr	⁷³Sr
39	⁷⁶Y
40	⁷⁷Zr