Element: Europium
General data
| Element name | Europium |
|---|---|
| Chemical symbol | Eu |
| Atomic number Z | 63 |
| Year discovered | 1901 |
| Standard state (25°C) | Solid |
| Category | Lanthanide |
| Block | f |
| Atomic mass | 151.96 |
| CPK color | #61FFC7 |
Physical properties
| Melting point | 1095 K (822 °C) |
|---|---|
| Boiling point | 1802 K (1529 °C) |
| Density | 5.24 g/cm³ |
Energy properties
| First ionization energy | 5.67 eV |
|---|---|
| Electron affinity | no data |
Atomic structure
| Protons | 63 (Atomic number) |
|---|---|
| Neutrons (Eu-153, most abundant isotope) | 90 |
| Electrons | 63 |
| Electron configuration | [Xe] 6s² 4f⁷ |
| Oxidation states | +3, +2 |
| Electronegativity (Pauling) | no data |
| Atomic radius (van der Waals) | 233 pm |
Ionization energies - NIST ASD (63 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Eu I | 0+ | 5.670385 ± 0.000005 | measured |
| Eu II | 1+ | 11.24 ± 0.006 | semi-empirical |
| Eu III | 2+ | 24.84 ± 0.03 | semi-empirical |
| Eu IV | 3+ | 42.94 ± 0.11 | semi-empirical |
| Eu V | 4+ | 63.2 ± 0.4 | semi-empirical |
| Eu VI | 5+ | 89 ± 4 | calculated |
| Eu VII | 6+ | 105 ± 5 | calculated |
| Eu VIII | 7+ | 120 ± 6 | calculated |
| Eu IX | 8+ | 144 ± 7 | calculated |
| Eu X | 9+ | 161 ± 8 | calculated |
| Eu XI | 10+ | 183 ± 9 | calculated |
| Eu XII | 11+ | 213 ± 11 | calculated |
| Eu XIII | 12+ | 243 ± 12 | calculated |
| Eu XIV | 13+ | 263 ± 14 | calculated |
| Eu XV | 14+ | 281 ± 14 | calculated |
| Eu XVI | 15+ | 311 ± 16 | calculated |
| Eu XVII | 16+ | 344.4 ± 0.5 | semi-empirical |
| Eu XVIII | 17+ | 518 ± 3 | calculated |
| Eu XIX | 18+ | 553 ± 3 | calculated |
| Eu XX | 19+ | 590 ± 4 | calculated |
| Eu XXI | 20+ | 630 ± 4 | calculated |
| Eu XXII | 21+ | 667 ± 4 | calculated |
| Eu XXIII | 22+ | 709 ± 4 | calculated |
| Eu XXIV | 23+ | 755 ± 4 | calculated |
| Eu XXV | 24+ | 795 ± 4 | calculated |
| Eu XXVI | 25+ | 838 ± 4 | calculated |
| Eu XXVII | 26+ | 879 ± 4 | calculated |
| Eu XXVIII | 27+ | 1037 ± 4 | calculated |
| Eu XXIX | 28+ | 1078 ± 4 | calculated |
| Eu XXX | 29+ | 1124 ± 4 | calculated |
| Eu XXXI | 30+ | 1167 ± 4 | calculated |
| Eu XXXII | 31+ | 1249 ± 4 | calculated |
| Eu XXXIII | 32+ | 1296 ± 4 | calculated |
| Eu XXXIV | 33+ | 1406 ± 5 | calculated |
| Eu XXXV | 34+ | 1456.06 ± 0.25 | semi-empirical |
| Eu XXXVI | 35+ | 2495 ± 5 | calculated |
| Eu XXXVII | 36+ | 2591 ± 5 | calculated |
| Eu XXXVIII | 37+ | 2697 ± 4 | calculated |
| Eu XXXIX | 38+ | 2807 ± 4 | calculated |
| Eu XL | 39+ | 2914 ± 4 | calculated |
| Eu XLI | 40+ | 3022 ± 4 | calculated |
| Eu XLII | 41+ | 3168 ± 4 | calculated |
| Eu XLIII | 42+ | 3279 ± 4 | calculated |
| Eu XLIV | 43+ | 3398 ± 4 | calculated |
| Eu XLV | 44+ | 3510 ± 4 | calculated |
| Eu XLVI | 45+ | 3823 ± 4 | calculated |
| Eu XLVII | 46+ | 3921 ± 4 | calculated |
| Eu XLVIII | 47+ | 4031 ± 4 | calculated |
| Eu XLIX | 48+ | 4131 ± 4 | calculated |
| Eu L | 49+ | 4400 ± 4 | calculated |
| Eu LI | 50+ | 4513 ± 4 | calculated |
| Eu LII | 51+ | 4729 ± 4 | calculated |
| Eu LIII | 52+ | 4838 ± 4 | calculated |
| Eu LIV | 53+ | 10880 ± 5 | calculated |
| Eu LV | 54+ | 11153 ± 5 | calculated |
| Eu LVI | 55+ | 11457 ± 5 | calculated |
| Eu LVII | 56+ | 11739 ± 5 | calculated |
| Eu LVIII | 57+ | 12718 ± 6 | calculated |
| Eu LIX | 58+ | 13050 ± 6 | calculated |
| Eu LX | 59+ | 13462 ± 7 | calculated |
| Eu LXI | 60+ | 13738.58 ± 0.09 | calculated |
| Eu LXII | 61+ | 55865.93 ± 0.08 | calculated |
| Eu LXIII | 62+ | 57120.64 ± 0.05 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
Photos
Isotopes (40)
| A | N | Half-life | Decay |
|---|---|---|---|
| Eu-130 | 67 | 0.9 ms | p |
| Eu-131 | 68 | 17.8 ms | p |
| Eu-132 | 69 | unknown | p |
| Eu-134 | 71 | 0.5 s | EC/β⁺ |
| Eu-135 | 72 | 1.5 s | EC/β⁺ |
| Eu-136 | 73 | 3.3 s | EC/β⁺ |
| Eu-137 | 74 | 11 s | EC/β⁺ |
| Eu-138 | 75 | 12.1 s | EC/β⁺ |
| Eu-139 | 76 | 17.9 s | EC/β⁺ |
| Eu-140 | 77 | 1.51 s | EC/β⁺ |
| Eu-141 | 78 | 40.7 s | EC/β⁺ |
| Eu-142 | 79 | 2.36 s | EC/β⁺ |
| Eu-143 | 80 | 2.60 min | EC/β⁺ |
| Eu-144 | 81 | 10.2 s | EC/β⁺ |
| Eu-145 | 82 | 5.93 d | EC/β⁺ |
| Eu-146 | 83 | 4.61 d | EC/β⁺ |
| Eu-147 | 84 | 24.1 d | EC |
| Eu-148 | 85 | 54.4 d | EC/β⁺ |
| Eu-149 | 86 | 93.1 d | EC |
| Eu-150 | 87 | 36.6 a | EC/β⁺ |
| Eu-151 | 88 | 4.6×10¹⁸ a | α |
| Eu-152 | 89 | 13.517 a | EC/β⁺ |
| Eu-153 | 90 | stable | - |
| Eu-154 | 91 | 8.591 a | β⁻ |
| Eu-155 | 92 | 4.742 a | β⁻ |
| Eu-156 | 93 | 15.16 d | β⁻ |
| Eu-157 | 94 | 15.18 h | β⁻ |
| Eu-158 | 95 | 45.9 min | β⁻ |
| Eu-159 | 96 | 18.10 min | β⁻ |
| Eu-160 | 97 | 42.6 s | β⁻ |
| Eu-161 | 98 | 26 s | β⁻ |
| Eu-162 | 99 | 11.7 s | β⁻ |
| Eu-163 | 100 | 7.7 s | β⁻ |
| Eu-164 | 101 | 4.08 s | β⁻ |
| Eu-165 | 102 | 2.25 s | β⁻ |
| Eu-166 | 103 | 1.29 s | β⁻ |
| Eu-167 | 104 | 860 ms | β⁻ |
| Eu-168 | 105 | 440 ms | β⁻ |
| Eu-169 | 106 | 390 ms | β⁻ |
| Eu-170 | 107 | 200 ms | β⁻ |
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce
- Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0