Cobalt-66

Properties and data of the isotope ⁶⁶Co.

Contents

General data

Name of the isotope:Cobalt-66; Co-66Symbol:⁶⁶Co or 6627CoMass number A:66 (= number of nucleons)Atomic number Z:27 (= number of protons)Neutrons N:39Isotopic mass:65.939443(15) u (atomic weight of Cobalt-66)Nuclide mass:65.9246317 u (calculated nuclear mass without electrons)Mass excess:-56.40848 MeVMass defect:0.609764588 u (per nucleus)Nuclear binding energy:567.99205513 MeV (per nucleus)
8.60594023 MeV (average binding energy per nucleon)Separation energy:S_N = 5.295(14) MeV (first neutron)
S_P = 12.480(15) MeV (first proton)Half-life:0.20(2) sDecay constant λ:3.4657359027997 s^-1Specific activity α:3.210946121538 × 10⁺²² Bq g^-1
867823276091.49 Ci g^-1Spin and parity:
(nuclear angular momentum)(3+)Year of discovery:1985

Radioactive Decay

Half-life T_½ = 0.20(2) s respectively 2.0 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁶⁶Ni	100 %	9.598(14) MeV

Parent Nuclides

Direct parent isotope is: ⁶⁶Fe.

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
^66m1Co	175 keV	1.21(1) μs	(5+)
^66m2Co	642 keV	100 μs	(8-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 39) and isobaric (same nucleon number A = 66) with Cobalt-66. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 39	Isobar A = 66
21	⁶⁰Sc
22	⁶¹Ti
23	⁶²V	⁶⁶V
24	⁶³Cr	⁶⁶Cr
25	⁶⁴Mn	⁶⁶Mn
26	⁶⁵Fe	⁶⁶Fe
27	⁶⁶Co	⁶⁶Co
28	⁶⁷Ni	⁶⁶Ni
29	⁶⁸Cu	⁶⁶Cu
30	⁶⁹Zn	⁶⁶Zn
31	⁷⁰Ga	⁶⁶Ga
32	⁷¹Ge	⁶⁶Ge
33	⁷²As	⁶⁶As
34	⁷³Se	⁶⁶Se
35	⁷⁴Br	⁶⁶Br
36	⁷⁵Kr
37	⁷⁶Rb
38	⁷⁷Sr
39	⁷⁸Y
40	⁷⁹Zr
42	⁸¹Mo