Krypton-77

Properties and data of the isotope ⁷⁷Kr.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Krypton-77; Kr-77Symbol:⁷⁷Kr or 7736KrMass number A:77 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:41Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.1388888888889 (= neutron-proton ratio)Neutron excess (N-Z):5Isotopic mass:76.9246700(21) u (atomic weight of Krypton-77)Nuclide mass:76.9049219 u (calculated nuclear mass without electrons)Mass excess:-70.16944 MeVMass defect:0.71229270799999 u (per nucleus)Nuclear binding energy:663.49638375 MeV (per nucleus)
8.61683615 MeV (average binding energy per nucleon)Separation energy:S_N = 9.227(4) MeV (first neutron)
S_P = 7.169(10) MeV (first proton)Half-life:74.4(6) minDecay constant λ:0.00015527490603941 s^-1Specific activity α:1.230378100240 × 10⁺¹⁸ Bq g^-1
33253462.168662 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = - 0.583(3)Quadrupole moment Q:0.94(10) barn (100 fm²)Nuclear g-factor:g_l = -0.2332Charge radius:4.2082(37) femtometer fmYear of discovery:1948

Radioactive Decay

Half-life T_½ = 74.4(6) min (minutes) respectively 4.464 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁷⁷Br	100 %	3.065(3) MeV

Parent Nuclides

Direct parent isotope is: ⁷⁷Rb.

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
^77mKr		118(12) ns	3/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 41) and isobaric (same nucleon number A = 77) with Krypton-77. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 41	Isobar A = 77
21	⁶²Sc
22	⁶³Ti
23	⁶⁴V
24	⁶⁵Cr
25	⁶⁶Mn
26	⁶⁷Fe
27	⁶⁸Co
28	⁶⁹Ni	⁷⁷Ni
29	⁷⁰Cu	⁷⁷Cu
30	⁷¹Zn	⁷⁷Zn
31	⁷²Ga	⁷⁷Ga
32	⁷³Ge	⁷⁷Ge
33	⁷⁴As	⁷⁷As
34	⁷⁵Se	⁷⁷Se
35	⁷⁶Br	⁷⁷Br
36	⁷⁷Kr	⁷⁷Kr
37	⁷⁸Rb	⁷⁷Rb
38	⁷⁹Sr	⁷⁷Sr
39	⁸⁰Y	⁷⁷Y
40	⁸¹Zr	⁷⁷Zr
41	⁸²Nb
42	⁸³Mo
44	⁸⁵Ru