Copper-55

Properties and data of the isotope ⁵⁵Cu.

Contents

General data

Name of the isotope:Copper-55; Cu-55Symbol:⁵⁵Cu or 5529CuMass number A:55 (= number of nucleons)Atomic number Z:29 (= number of protons)Neutrons N:26Isotopic mass:54.96604(17) u (atomic weight of Copper-55)Nuclide mass:54.9501316 u (calculated nuclear mass without electrons)Mass excess:-31.63354 MeVMass defect:0.48617374400001 u (per nucleus)Nuclear binding energy:452.86792549 MeV (per nucleus)
8.23396228 MeV (average binding energy per nucleon)Separation energy:S_N = 18.30(43) MeV (first neutron)Half-life:40 msDecay constant λ:17.328679513999 s^-1Specific activity α:1.932513869444 × 10⁺²³ Bq g^-1
5223010457957.8 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2-Mirror nucleus:Iron-55Year of discovery:1987

Radioactive Decay

Half-life T_½ = 40 ms respectively 4.0 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy
β⁺	⁵⁵Ni		13.70(16) MeV
p	⁵⁴Ni	?
EC, p	⁵⁴Co	15(4) %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 26) and isobaric (same nucleon number A = 55) with Copper-55. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 26	Isobar A = 55
11	³⁷Na
12	³⁸Mg
13	³⁹Al
14	⁴⁰Si
15	⁴¹P
16	⁴²S
17	⁴³Cl
18	⁴⁴Ar
19	⁴⁵K	⁵⁵K
20	⁴⁶Ca	⁵⁵Ca
21	⁴⁷Sc	⁵⁵Sc
22	⁴⁸Ti	⁵⁵Ti
23	⁴⁹V	⁵⁵V
24	⁵⁰Cr	⁵⁵Cr
25	⁵¹Mn	⁵⁵Mn
26	⁵²Fe	⁵⁵Fe
27	⁵³Co	⁵⁵Co
28	⁵⁴Ni	⁵⁵Ni
29	⁵⁵Cu	⁵⁵Cu
30	⁵⁶Zn	⁵⁵Zn