Silver-128

Properties and data of the isotope ¹²⁸Ag.

Content

General data

Name of the isotope:Silver-128; Ag-128Symbol:¹²⁸Ag or 12847AgMass number A:128 (= number of nucleons)Atomic number Z:47 (= number of protons)Neutrons N:81Isotopic mass:127.94136(32) u (atomic weight of Silver-128)Nuclide mass:127.9155781 u (calculated nuclear mass without electrons)Mass excess:-54.62281 MeVMass defect:1.1282747 u (per nucleus)Nuclear binding energy:1050.9811134 MeV (per nucleus)
8.21078995 MeV (average binding energy per nucleon)Separation energy:S_N = 4.25(36) MeV (first neutron)
S_P = 14.73(58) MeV (first proton)Half-life:58(5) msDecay constant λ:11.95081345793 s^-1Specific activity α:5.666888349171 × 10⁺²² Bq g^-1
1531591445722.1 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2000

Radioactive Decay

Half-life T_½ = 58(5) ms respectively 5.8 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹²⁸Cd	100 %	12.62(30) MeV
β^-, n	¹²⁷Cd	?	6.06(30) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 81) and isobaric (same nucleon number A = 128) with Silver-128. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 81	Isobar A = 128
45	¹²⁶Rh
46	¹²⁷Pd	¹²⁸Pd
47	¹²⁸Ag	¹²⁸Ag
48	¹²⁹Cd	¹²⁸Cd
49	¹³⁰In	¹²⁸In
50	¹³¹Sn	¹²⁸Sn
51	¹³²Sb	¹²⁸Sb
52	¹³³Te	¹²⁸Te
53	¹³⁴I	¹²⁸I
54	¹³⁵Xe	¹²⁸Xe
55	¹³⁶Cs	¹²⁸Cs
56	¹³⁷Ba	¹²⁸Ba
57	¹³⁸La	¹²⁸La
58	¹³⁹Ce	¹²⁸Ce
59	¹⁴⁰Pr	¹²⁸Pr
60	¹⁴¹Nd	¹²⁸Nd
61	¹⁴²Pm	¹²⁸Pm
62	¹⁴³Sm	¹²⁸Sm
63	¹⁴⁴Eu
64	¹⁴⁵Gd
65	¹⁴⁶Tb
66	¹⁴⁷Dy
67	¹⁴⁸Ho
68	¹⁴⁹Er
69	¹⁵⁰Tm
70	¹⁵¹Yb
71	¹⁵²Lu
72	¹⁵³Hf