Krypton-68

Properties and data of the isotope ⁶⁸Kr.

Contents

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

General data

Name of the isotope:Krypton-68; Kr-68Symbol:⁶⁸Kr or 6836KrMass number A:68 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:32Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):0.88888888888889 (= neutron-proton ratio)Neutron excess (N-Z):-4Isotopic mass:67.97249(54) u (atomic weight of Krypton-68)Nuclide mass:67.9527419 u (calculated nuclear mass without electrons)Mass excess:-25.6254 MeVMass defect:0.58648846400001 u (per nucleus)Nuclear binding energy:546.31048529 MeV (per nucleus)
8.03397772 MeV (average binding energy per nucleon)Separation energy:S_N = 18.146(656) MeV (first neutron)
S_P = 0.386(583) MeV (first proton)Half-life:21.6(33) msDecay constant λ:32.090147248146 s^-1Specific activity α:2.884349058872 × 10⁺²³ Bq g^-1
7795537996952.2 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Mirror nucleus:Germanium-68Year of discovery:2016

Radioactive Decay

Half-life T_½ = 21.6(33) ms respectively 2.16 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁶⁸Br	11 %
EC, p	⁶⁷Se	89 %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 32) and isobaric (same nucleon number A = 68) with Krypton-68. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 32	Isobar A = 68
15	⁴⁷P
16	⁴⁸S
17	⁴⁹Cl
18	⁵⁰Ar
19	⁵¹K
20	⁵²Ca
21	⁵³Sc
22	⁵⁴Ti
23	⁵⁵V	⁶⁸V
24	⁵⁶Cr	⁶⁸Cr
25	⁵⁷Mn	⁶⁸Mn
26	⁵⁸Fe	⁶⁸Fe
27	⁵⁹Co	⁶⁸Co
28	⁶⁰Ni	⁶⁸Ni
29	⁶¹Cu	⁶⁸Cu
30	⁶²Zn	⁶⁸Zn
31	⁶³Ga	⁶⁸Ga
32	⁶⁴Ge	⁶⁸Ge
33	⁶⁵As	⁶⁸As
34	⁶⁶Se	⁶⁸Se
35	⁶⁷Br	⁶⁸Br
36	⁶⁸Kr	⁶⁸Kr