Promethium-127

Properties and data of the isotope ¹²⁷Pm.

Content

General data

Name of the isotope:Promethium-127; Pm-127Symbol:¹²⁷Pm or 12761PmMass number A:127 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:66Isotopic mass:126.95163(64) u (atomic weight of Promethium-127)Nuclide mass:126.9181692 u (calculated nuclear mass without electrons)Mass excess:-45.05636 MeVMass defect:1.097581408 u (per nucleus)Nuclear binding energy:1022.39049606 MeV (per nucleus)
8.05031887 MeV (average binding energy per nucleon)Half-life:~ 1 sDecay constant λ:0.69314718055995 s^-1Specific activity α:3.312880919047 × 10⁺²¹ Bq g^-1
89537322136.422 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+~

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 66) and isobaric (same nucleon number A = 127) with Promethium-127. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 66	Isobar A = 127
37	¹⁰³Rb
38	¹⁰⁴Sr
39	¹⁰⁵Y
40	¹⁰⁶Zr
41	¹⁰⁷Nb
42	¹⁰⁸Mo
43	¹⁰⁹Tc
44	¹¹⁰Ru
45	¹¹¹Rh	¹²⁷Rh
46	¹¹²Pd	¹²⁷Pd
47	¹¹³Ag	¹²⁷Ag
48	¹¹⁴Cd	¹²⁷Cd
49	¹¹⁵In	¹²⁷In
50	¹¹⁶Sn	¹²⁷Sn
51	¹¹⁷Sb	¹²⁷Sb
52	¹¹⁸Te	¹²⁷Te
53	¹¹⁹I	¹²⁷I
54	¹²⁰Xe	¹²⁷Xe
55	¹²¹Cs	¹²⁷Cs
56	¹²²Ba	¹²⁷Ba
57	¹²³La	¹²⁷La
58	¹²⁴Ce	¹²⁷Ce
59	¹²⁵Pr	¹²⁷Pr
60	¹²⁶Nd	¹²⁷Nd
61	¹²⁷Pm	¹²⁷Pm
62	¹²⁸Sm