Element: Xenon
General data
| Element name | Xenon |
|---|---|
| Chemical symbol | Xe |
| Atomic number Z | 54 |
| Year discovered | 1898 |
| Standard state (25°C) | Gas |
| Category | Noble gas |
| Block | p |
| Atomic mass | 131.29 |
| CPK color | #429EB0 |
Physical properties
| Melting point | 161.36 K (-111.79 °C) |
|---|---|
| Boiling point | 165.03 K (-108.12 °C) |
| Density | 0.005887 g/cm³ |
Energy properties
| First ionization energy | 12.13 eV |
|---|---|
| Electron affinity | no data |
Atomic structure
| Protons | 54 (Atomic number) |
|---|---|
| Neutrons (Xe-132, most abundant isotope) | 78 |
| Electrons | 54 |
| Electron configuration | [Kr] 5s² 4d¹⁰ 5p⁶ |
| Oxidation states | no data |
| Electronegativity (Pauling) | 2.6 |
| Atomic radius (van der Waals) | 216 pm |
Ionization energies - NIST ASD (54 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Xe I | 0+ | 12.1298437 ± 0.0000015 | measured |
| Xe II | 1+ | 20.975 ± 0.004 | semi-empirical |
| Xe III | 2+ | 31.05 ± 0.04 | semi-empirical |
| Xe IV | 3+ | 42.2 ± 0.2 | measured |
| Xe V | 4+ | 54.1 ± 0.5 | semi-empirical |
| Xe VI | 5+ | 66.703 ± 0.007 | measured |
| Xe VII | 6+ | 91.6 ± 0.5 | semi-empirical |
| Xe VIII | 7+ | 105.9778 ± 0.0025 | measured |
| Xe IX | 8+ | 179.84 ± 0.12 | measured |
| Xe X | 9+ | 202 ± 2.2 | calculated |
| Xe XI | 10+ | 229.02 ± 0.2 | semi-empirical |
| Xe XII | 11+ | 255 ± 2.5 | calculated |
| Xe XIII | 12+ | 281 ± 3 | calculated |
| Xe XIV | 13+ | 314 ± 3 | calculated |
| Xe XV | 14+ | 343 ± 3 | calculated |
| Xe XVI | 15+ | 374 ± 3 | calculated |
| Xe XVII | 16+ | 404 ± 3 | calculated |
| Xe XVIII | 17+ | 434 ± 3 | calculated |
| Xe XIX | 18+ | 549 ± 3 | calculated |
| Xe XX | 19+ | 582 ± 4 | calculated |
| Xe XXI | 20+ | 616 ± 4 | calculated |
| Xe XXII | 21+ | 650 ± 4 | calculated |
| Xe XXIII | 22+ | 700 ± 4 | calculated |
| Xe XXIV | 23+ | 736 ± 4 | calculated |
| Xe XXV | 24+ | 818 ± 4 | calculated |
| Xe XXVI | 25+ | 857 ± 0.4 | semi-empirical |
| Xe XXVII | 26+ | 1493 ± 4 | calculated |
| Xe XXVIII | 27+ | 1571 ± 4 | calculated |
| Xe XXIX | 28+ | 1653 ± 4 | calculated |
| Xe XXX | 29+ | 1742 ± 4 | calculated |
| Xe XXXI | 30+ | 1826 ± 4 | calculated |
| Xe XXXII | 31+ | 1919 ± 4 | calculated |
| Xe XXXIII | 32+ | 2023 ± 4 | calculated |
| Xe XXXIV | 33+ | 2113 ± 5 | calculated |
| Xe XXXV | 34+ | 2209 ± 5 | calculated |
| Xe XXXVI | 35+ | 2300 ± 5 | calculated |
| Xe XXXVII | 36+ | 2556 ± 5 | calculated |
| Xe XXXVIII | 37+ | 2637 ± 4 | calculated |
| Xe XXXIX | 38+ | 2726 ± 4 | calculated |
| Xe XL | 39+ | 2811 ± 4 | calculated |
| Xe XLI | 40+ | 2975 ± 4 | calculated |
| Xe XLII | 41+ | 3068 ± 4 | calculated |
| Xe XLIII | 42+ | 3243 ± 4 | calculated |
| Xe XLIV | 43+ | 3333.8 ± 0.5 | semi-empirical |
| Xe XLV | 44+ | 7660 ± 4 | calculated |
| Xe XLVI | 45+ | 7889 ± 4 | calculated |
| Xe XLVII | 46+ | 8144 ± 4 | calculated |
| Xe XLVIII | 47+ | 8382 ± 4 | calculated |
| Xe XLIX | 48+ | 8971 ± 4 | calculated |
| Xe L | 49+ | 9243 ± 4 | calculated |
| Xe LI | 50+ | 9581 ± 4 | calculated |
| Xe LII | 51+ | 9810.37 ± 0.04 | calculated |
| Xe LIII | 52+ | 40271.73 ± 0.03 | calculated |
| Xe LIV | 53+ | 41299.892 ± 0.019 | 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 (43)
| A | N | Half-life | Decay |
|---|---|---|---|
| Xe-108 | 54 | 60 μs | α |
| Xe-109 | 55 | 13 ms | α |
| Xe-110 | 56 | 93 ms | α |
| Xe-111 | 57 | 0.74 s | EC/β⁺ |
| Xe-112 | 58 | 2.7 s | EC/β⁺ |
| Xe-113 | 59 | 2.74 s | EC/β⁺ |
| Xe-114 | 60 | 10.0 s | EC/β⁺ |
| Xe-115 | 61 | 18 s | EC/β⁺ |
| Xe-116 | 62 | 58 s | EC/β⁺ |
| Xe-117 | 63 | 61 s | EC/β⁺ |
| Xe-118 | 64 | 3.8 min | EC/β⁺ |
| Xe-119 | 65 | 5.8 min | EC/β⁺ |
| Xe-120 | 66 | 46.0 min | EC/β⁺ |
| Xe-121 | 67 | 39.1 min | EC/β⁺ |
| Xe-122 | 68 | 20.1 h | EC |
| Xe-123 | 69 | 2.050 h | EC/β⁺ |
| Xe-124 | 70 | stable | - |
| Xe-125 | 71 | 16.96 h | EC/β⁺ |
| Xe-126 | 72 | stable | - |
| Xe-127 | 73 | 36.344 d | EC |
| Xe-128 | 74 | stable | - |
| Xe-129 | 75 | stable | - |
| Xe-130 | 76 | stable | - |
| Xe-131 | 77 | stable | - |
| Xe-132 | 78 | stable | - |
| Xe-133 | 79 | 5.2474 d | β⁻ |
| Xe-134 | 80 | stable | - |
| Xe-135 | 81 | 9.168 h | β⁻ |
| Xe-136 | 82 | 2.19×10²¹ a | 2β⁻ |
| Xe-137 | 83 | 3.821 min | β⁻ |
| Xe-138 | 84 | 14.14 min | β⁻ |
| Xe-139 | 85 | 39.72 s | β⁻ |
| Xe-140 | 86 | 13.6 s | β⁻ |
| Xe-141 | 87 | 1.720 s | β⁻ |
| Xe-142 | 88 | 1.227 s | β⁻ |
| Xe-143 | 89 | 511 ms | β⁻ |
| Xe-144 | 90 | 388 ms | β⁻ |
| Xe-145 | 91 | 188 ms | β⁻ |
| Xe-146 | 92 | 146 ms | β⁻ |
| Xe-147 | 93 | 88 ms | β⁻ |
| Xe-148 | 94 | 85 ms | β⁻ |
| Xe-149 | 95 | unknown | β⁻ |
| Xe-150 | 96 | unknown | 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