Krypton-72

Properties and data of the isotope ⁷²Kr.

Content

General data

Name of the isotope:Krypton-72; Kr-72Symbol:⁷²Kr or 7236KrMass number A:72 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:36Isotopic mass:71.942092(9) u (atomic weight of Krypton-72)Nuclide mass:71.9223439 u (calculated nuclear mass without electrons)Mass excess:-53.94095 MeVMass defect:0.65154612800001 u (per nucleus)Nuclear binding energy:606.91130896 MeV (per nucleus)
8.42932374 MeV (average binding energy per nucleon)Separation energy:S_N = 15.68(13) MeV (first neutron)
S_P = 4.727(10) MeV (first proton)Half-life:17.1(2) sDecay constant λ:0.040534922839763 s^-1Specific activity α:3.438126973066 × 10⁺²⁰ Bq g^-1
9292235062.3419 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.1635(60) femtometer fmYear of discovery:1973

Radioactive Decay

Half-life T_½ = 17.1(2) s respectively 1.71 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	⁷²Br	> 99 %	5.121(8) MeV
EE, p	⁷¹Se	< 1 %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 36) and isobaric (same nucleon number A = 72) with Krypton-72. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 36	Isobar A = 72
19	⁵⁵K
20	⁵⁶Ca
21	⁵⁷Sc
22	⁵⁸Ti
23	⁵⁹V
24	⁶⁰Cr
25	⁶¹Mn
26	⁶²Fe	⁷²Fe
27	⁶³Co	⁷²Co
28	⁶⁴Ni	⁷²Ni
29	⁶⁵Cu	⁷²Cu
30	⁶⁶Zn	⁷²Zn
31	⁶⁷Ga	⁷²Ga
32	⁶⁸Ge	⁷²Ge
33	⁶⁹As	⁷²As
34	⁷⁰Se	⁷²Se
35	⁷¹Br	⁷²Br
36	⁷²Kr	⁷²Kr
37	⁷³Rb	⁷²Rb
38	⁷⁴Sr