Europium-149
Properties and data of the isotope 149Eu.
See also: List of individual Europium isotopes (and general data sources).
General data
Name of the isotope:Europium-149; Eu-149Symbol:149Eu or 14963EuMass number A:149 (= number of nucleons)Atomic number Z:63 (= number of protons)Neutrons N:86Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3650793650794 (= neutron-proton ratio)Neutron excess (N-Z):23Isotopic mass:148.917937(4) u (atomic weight of Europium-149)Nuclide mass:148.8833792 u (calculated nuclear mass without electrons)Mass excess:-76.44119 MeVMass defect:1.320222792 u (per nucleus)Nuclear binding energy:1229.77960941 MeV (per nucleus)
8.25355443 MeV (average binding energy per nucleon)Separation energy:SN = 8.213(11) MeV (first neutron)
SP = 4.494(4) MeV (first proton)Half-life:93.1(4) dDecay constant λ:8.617117950629 × 10-8 s-1Specific activity α:3.506317439552 × 10+14 Bq g-1
9476.5336204132 Ci g-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μN) = + 3.565(6)Quadrupole moment Q:+0.716(17) barn (100 fm2)Nuclear g-factor:gl = 1.426Charge radius:5.0202(103) femtometer fmYear of discovery:1959
Radioactive Decay
Half-life T½ = 93.1(4) d respectively 8.043840 × 106 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC | 149Sm | 100 % | 0.695(4) MeV | |
Parent Nuclides
Direct parent isotope is: 149Gd.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 86) and isobaric (same nucleon number A = 149) with Europium-149. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 86 | Isobar A = 149 |
|---|
| 48 | 134Cd | |
| 49 | 135In | |
| 50 | 136Sn | |
| 51 | 137Sb | |
| 52 | 138Te | |
| 53 | 139I | |
| 54 | 140Xe | |
| 55 | 141Cs | 149Cs |
| 56 | 142Ba | 149Ba |
| 57 | 143La | 149La |
| 58 | 144Ce | 149Ce |
| 59 | 145Pr | 149Pr |
| 60 | 146Nd | 149Nd |
| 61 | 147Pm | 149Pm |
| 62 | 148Sm | 149Sm |
| 63 | 149Eu | 149Eu |
| 64 | 150Gd | 149Gd |
| 65 | 151Tb | 149Tb |
| 66 | 152Dy | 149Dy |
| 67 | 153Ho | 149Ho |
| 68 | 154Er | 149Er |
| 69 | 155Tm | 149Tm |
| 70 | 156Yb | 149Yb |
| 71 | 157Lu | 149Lu |
| 72 | 158Hf | |
| 73 | 159Ta | |
| 74 | 160W | |
| 75 | 161Re | |
| 76 | 162Os | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/europium-149
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