Rhodium-122

Properties and data of the isotope ¹²²Rh.

Contents

See also: List of individual Rhodium isotopes (and general data sources).

General data

Name of the isotope:Rhodium-122; Rh-122Symbol:¹²²Rh or 12245RhMass number A:122 (= number of nucleons)Atomic number Z:45 (= number of protons)Neutrons N:77Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.7111111111111 (= neutron-proton ratio)Neutron excess (N-Z):32Isotopic mass:121.94409(32) u (atomic weight of Rhodium-122)Nuclide mass:121.9194052 u (calculated nuclear mass without electrons)Mass excess:-52.07983 MeVMass defect:1.075234972 u (per nucleus)Nuclear binding energy:1001.57492501 MeV (per nucleus)
8.20963053 MeV (average binding energy per nucleon)Separation energy:S_N = 3.90(69) MeV (first neutron)
S_P = 14.32(50) MeV (first proton)Half-life:300 nsDecay constant λ:2310490.6018665 s^-1Specific activity α:1.149925608264 × 10⁺²⁸ Bq g^-1
3.107907049363 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1997

Radioactive Decay

Half-life T_½ = 300 ns respectively 3.0 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	¹²²Pd	?	12.54(30) MeV
β^-, n	¹²¹Pd	?	6.03(30) MeV
β^-, 2n	¹²⁰Pd	?

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
^122mRh	271.0(7) keV	0.82 μs

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 77) and isobaric (same nucleon number A = 122) with Rhodium-122. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 77	Isobar A = 122
43	¹²⁰Tc
44	¹²¹Ru	¹²²Ru
45	¹²²Rh	¹²²Rh
46	¹²³Pd	¹²²Pd
47	¹²⁴Ag	¹²²Ag
48	¹²⁵Cd	¹²²Cd
49	¹²⁶In	¹²²In
50	¹²⁷Sn	¹²²Sn
51	¹²⁸Sb	¹²²Sb
52	¹²⁹Te	¹²²Te
53	¹³⁰I	¹²²I
54	¹³¹Xe	¹²²Xe
55	¹³²Cs	¹²²Cs
56	¹³³Ba	¹²²Ba
57	¹³⁴La	¹²²La
58	¹³⁵Ce	¹²²Ce
59	¹³⁶Pr	¹²²Pr
60	¹³⁷Nd
61	¹³⁸Pm
62	¹³⁹Sm
63	¹⁴⁰Eu
64	¹⁴¹Gd
65	¹⁴²Tb
66	¹⁴³Dy
67	¹⁴⁴Ho
68	¹⁴⁵Er
69	¹⁴⁶Tm