Rhodium-121
Properties and data of the isotope 121Rh.
See also: List of individual Rhodium isotopes (and general data sources).
General data
Name of the isotope:Rhodium-121; Rh-121Symbol:121Rh or 12145RhMass number A:121 (= number of nucleons)Atomic number Z:45 (= number of protons)Neutrons N:76Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.6888888888889 (= neutron-proton ratio)Neutron excess (N-Z):31Isotopic mass:120.93961(66) u (atomic weight of Rhodium-121)Nuclide mass:120.9149252 u (calculated nuclear mass without electrons)Mass excess:-56.25292 MeVMass defect:1.071050056 u (per nucleus)Nuclear binding energy:997.67670086 MeV (per nucleus)
8.24526199 MeV (average binding energy per nucleon)Separation energy:SN = 5.51(65) MeV (first neutron)
SP = 13.53(74) MeV (first proton)Half-life:151 msDecay constant λ:4.5903786792049 s-1Specific activity α:2.303658917218 × 10+22 Bq g-1
622610518167.16 Ci g-1Spin and parity:
(nuclear angular momentum)Year of discovery:1994
Radioactive Decay
Half-life T½ = 151 ms respectively 1.51 × 10-1 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 121Pd | < 100 % | 9.93(62) MeV | |
| β-, n | 120Pd | ? | 5.96(62) MeV | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 76) and isobaric (same nucleon number A = 121) with Rhodium-121. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 76 | Isobar A = 121 |
|---|
| 42 | 118Mo | |
| 43 | 119Tc | 121Tc |
| 44 | 120Ru | 121Ru |
| 45 | 121Rh | 121Rh |
| 46 | 122Pd | 121Pd |
| 47 | 123Ag | 121Ag |
| 48 | 124Cd | 121Cd |
| 49 | 125In | 121In |
| 50 | 126Sn | 121Sn |
| 51 | 127Sb | 121Sb |
| 52 | 128Te | 121Te |
| 53 | 129I | 121I |
| 54 | 130Xe | 121Xe |
| 55 | 131Cs | 121Cs |
| 56 | 132Ba | 121Ba |
| 57 | 133La | 121La |
| 58 | 134Ce | 121Ce |
| 59 | 135Pr | 121Pr |
| 60 | 136Nd | |
| 61 | 137Pm | |
| 62 | 138Sm | |
| 63 | 139Eu | |
| 64 | 140Gd | |
| 65 | 141Tb | |
| 66 | 142Dy | |
| 67 | 143Ho | |
| 68 | 144Er | |
| 69 | 145Tm | |
External data and identifiers
Last update: 2020-10-15
Perma link: https://www.chemlin.org/isotope/rhodium-121
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