Cobalt-60m

Properties and data of the isotope ^60mCo.

Contents

General data

Name of the isotope:Cobalt-60m; Co-60mSymbol:^60mCo or 60m27CoMass number A:60 (= number of nucleons)Atomic number Z:27 (= number of protons)Neutrons N:33Isotopic mass:59.9338157(5) u (atomic weight of Cobalt-60m)
Excitation energy: 58.59(1) keVNuclide mass:59.9190044 u (calculated nuclear mass without electrons)Mass excess:-61.65028 MeVMass defect:0.563402392 u (per nucleus)Nuclear binding energy:524.80594773 MeV (per nucleus)
8.7467658 MeV (average binding energy per nucleon)Half-life:10.467(6) minDecay constant λ:0.0011037023989044 s^-1Specific activity α:1.126551070110 × 10⁺¹⁹ Bq g^-1
304473262.19205 Ci g^-1Spin and parity:
(nuclear angular momentum)2+Magnetic dipole moment:μ(μ_N) = + 4.40(9)Quadrupole moment Q:+ 0.3(4) barn (100 fm²)Nuclear g-factor:g_l = 2.2

Radioactive Decay

Half-life T_½ = 10.467(6) min (minutes) respectively 6.2802 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	⁶⁰Co	99.75(3) %	0.059 MeV
β^-	⁶⁰Ni	0.25(3) %	1.56 MeV

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
⁶⁰Co		5.2713(8) a	5+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 33) and isobaric (same nucleon number A = 60) with Cobalt-60m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 33	Isobar A = 60
16	⁴⁹S
17	⁵⁰Cl
18	⁵¹Ar
19	⁵²K
20	⁵³Ca
21	⁵⁴Sc	⁶⁰Sc
22	⁵⁵Ti	⁶⁰Ti
23	⁵⁶V	⁶⁰V
24	⁵⁷Cr	⁶⁰Cr
25	⁵⁸Mn	⁶⁰Mn
26	⁵⁹Fe	⁶⁰Fe
27	⁶⁰Co	⁶⁰Co
28	⁶¹Ni	⁶⁰Ni
29	⁶²Cu	⁶⁰Cu
30	⁶³Zn	⁶⁰Zn
31	⁶⁴Ga	⁶⁰Ga
32	⁶⁵Ge	⁶⁰Ge
33	⁶⁶As
34	⁶⁷Se
35	⁶⁸Br
36	⁶⁹Kr