Copper-81

Properties and data of the isotope ⁸¹Cu.

Content

General data

Name of the isotope:Copper-81; Cu-81Symbol:⁸¹Cu or 8129CuMass number A:81 (= number of nucleons)Atomic number Z:29 (= number of protons)Neutrons N:52Isotopic mass:80.96627(54) u (atomic weight of Copper-81)Nuclide mass:80.9503616 u (calculated nuclear mass without electrons)Mass excess:-31.41929 MeVMass defect:0.71123156 u (per nucleus)Nuclear binding energy:662.50793075 MeV (per nucleus)
8.17911026 MeV (average binding energy per nucleon)Separation energy:S_N = 3.29(64) MeV (first neutron)
S_P = 16.08(86) MeV (first proton)Half-life:73.2(68) msDecay constant λ:9.4692237781413 s^-1Specific activity α:7.128124928278 × 10⁺²² Bq g^-1
1926520250886.1 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2010

Radioactive Decay

Half-life T_½ = 73.2(68) ms respectively 7.32 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	⁸¹Zn	100 %	14.78(59) MeV
β^-, n	⁸⁰Zn	?	12.16(50) MeV
β^-, 2n	⁷⁹Zn	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 52) and isobaric (same nucleon number A = 81) with Copper-81. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 52	Isobar A = 81
28	⁸⁰Ni
29	⁸¹Cu	⁸¹Cu
30	⁸²Zn	⁸¹Zn
31	⁸³Ga	⁸¹Ga
32	⁸⁴Ge	⁸¹Ge
33	⁸⁵As	⁸¹As
34	⁸⁶Se	⁸¹Se
35	⁸⁷Br	⁸¹Br
36	⁸⁸Kr	⁸¹Kr
37	⁸⁹Rb	⁸¹Rb
38	⁹⁰Sr	⁸¹Sr
39	⁹¹Y	⁸¹Y
40	⁹²Zr	⁸¹Zr
41	⁹³Nb	⁸¹Nb
42	⁹⁴Mo	⁸¹Mo
43	⁹⁵Tc
44	⁹⁶Ru
45	⁹⁷Rh
46	⁹⁸Pd
47	⁹⁹Ag
48	¹⁰⁰Cd
49	¹⁰¹In
50	¹⁰²Sn
51	¹⁰³Sb