Cobalt-61

Properties and data of the isotope ⁶¹Co.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

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

General data

Name of the isotope:Cobalt-61; Co-61Symbol:⁶¹Co or 6127CoMass number A:61 (= number of nucleons)Atomic number Z:27 (= number of protons)Neutrons N:34Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.2592592592593 (= neutron-proton ratio)Neutron excess (N-Z):7Isotopic mass:60.9324760(9) u (atomic weight of Cobalt-61)Nuclide mass:60.9176647 u (calculated nuclear mass without electrons)Mass excess:-62.8982 MeVMass defect:0.573407008 u (per nucleus)Nuclear binding energy:534.12518751 MeV (per nucleus)
8.75615061 MeV (average binding energy per nucleon)Separation energy:S_N = 9.3191(8) MeV (first neutron)
S_P = 8.774(3) MeV (first proton)Half-life:1.649(5) hDecay constant λ:0.00011676220951417 s^-1Specific activity α:1.171930788019 × 10⁺¹⁸ Bq g^-1
31673805.081614 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2-Year of discovery:1947

Radioactive Decay

Half-life T_½ = 1.649(5) h (hours) respectively 5.9364 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁶¹Ni	100 %	1.3239(8) MeV	0.067412(10) MeV 84.7(4) %

Parent Nuclides

Direct parent isotope is: ⁶¹Fe.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 34) and isobaric (same nucleon number A = 61) with Cobalt-61. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 34	Isobar A = 61
17	⁵¹Cl
18	⁵²Ar
19	⁵³K
20	⁵⁴Ca
21	⁵⁵Sc	⁶¹Sc
22	⁵⁶Ti	⁶¹Ti
23	⁵⁷V	⁶¹V
24	⁵⁸Cr	⁶¹Cr
25	⁵⁹Mn	⁶¹Mn
26	⁶⁰Fe	⁶¹Fe
27	⁶¹Co	⁶¹Co
28	⁶²Ni	⁶¹Ni
29	⁶³Cu	⁶¹Cu
30	⁶⁴Zn	⁶¹Zn
31	⁶⁵Ga	⁶¹Ga
32	⁶⁶Ge	⁶¹Ge
33	⁶⁷As
34	⁶⁸Se
35	⁶⁹Br
36	⁷⁰Kr
37	⁷¹Rb