Samarium-151
Properties and data of the isotope 151Sm.
See also: List of individual Samarium isotopes (and general data sources).
General data
Name of the isotope:Samarium-151; Sm-151Symbol:151Sm or 15162SmMass number A:151 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:89Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4354838709677 (= neutron-proton ratio)Neutron excess (N-Z):27Isotopic mass:150.9199391(14) u (atomic weight of Samarium-151)Nuclide mass:150.8859298 u (calculated nuclear mass without electrons)Mass excess:-74.57625 MeVMass defect:1.336390408 u (per nucleus)Nuclear binding energy:1244.83964671 MeV (per nucleus)
8.24397117 MeV (average binding energy per nucleon)Separation energy:SN = 5.59646(11) MeV (first neutron)
SP = 8.268(20) MeV (first proton)Half-life:90(8) aDecay constant λ:2.442379071740 × 10-10 s-1Specific activity α:980556720225.51 Bq g-1
26.501532979068 Ci g-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μN) = - 0.363Quadrupole moment Q:+0.71(7) barn (100 fm2)Nuclear g-factor:gl = -0.1452Charge radius:5.0550(57) femtometer fmYear of discovery:1947
Radioactive Decay
Half-life T½ = 90(8) a respectively 2.838 × 109 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 151Eu | 100 % | 0.0766(5) MeV | |
Parent Nuclides
Direct parent isotope is: 151Pm.
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 |
|---|
| 151mSm | 261.13(4) keV | 1.4(1) μs | (11/2)- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 89) and isobaric (same nucleon number A = 151) with Samarium-151. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 89 | Isobar A = 151 |
|---|
| 50 | 139Sn | |
| 51 | 140Sb | |
| 52 | 141Te | |
| 53 | 142I | |
| 54 | 143Xe | |
| 55 | 144Cs | 151Cs |
| 56 | 145Ba | 151Ba |
| 57 | 146La | 151La |
| 58 | 147Ce | 151Ce |
| 59 | 148Pr | 151Pr |
| 60 | 149Nd | 151Nd |
| 61 | 150Pm | 151Pm |
| 62 | 151Sm | 151Sm |
| 63 | 152Eu | 151Eu |
| 64 | 153Gd | 151Gd |
| 65 | 154Tb | 151Tb |
| 66 | 155Dy | 151Dy |
| 67 | 156Ho | 151Ho |
| 68 | 157Er | 151Er |
| 69 | 158Tm | 151Tm |
| 70 | 159Yb | 151Yb |
| 71 | 160Lu | 151Lu |
| 72 | 161Hf | |
| 73 | 162Ta | |
| 74 | 163W | |
| 75 | 164Re | |
| 76 | 165Os | |
| 77 | 166Ir | |
| 78 | 167Pt | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/samarium-151
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