Element: Tellurium
General data
| Element name | Tellurium |
|---|---|
| Chemical symbol | Te |
| Atomic number Z | 52 |
| Year discovered | 1782 |
| Standard state (25°C) | Solid |
| Category | Metalloid |
| Block | p |
| Atomic mass | 127.60 |
| CPK color | #D47A00 |
Physical properties
| Melting point | 722.66 K (449.51 °C) |
|---|---|
| Boiling point | 1261 K (988 °C) |
| Density | 6.232 g/cm³ |
Energy properties
| First ionization energy | 9.01 eV |
|---|---|
| Electron affinity | 1.971 eV |
Atomic structure
| Protons | 52 (Atomic number) |
|---|---|
| Neutrons (Te-130, most abundant isotope) | 78 |
| Electrons | 52 |
| Electron configuration | [Kr] 5s² 4d¹⁰ 5p⁴ |
| Oxidation states | +6, +4, -2 |
| Electronegativity (Pauling) | 2.1 |
| Atomic radius (van der Waals) | 206 pm |
Ionization energies - NIST ASD (52 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Te I | 0+ | 9.009808 ± 0.000006 | measured |
| Te II | 1+ | 18.6 ± 0.4 | measured |
| Te III | 2+ | 27.84 ± 0.04 | measured |
| Te IV | 3+ | 37.4155 ± 0.0012 | measured |
| Te V | 4+ | 59.3 ± 0.9 | measured |
| Te VI | 5+ | 69.1 ± 2 | calculated |
| Te VII | 6+ | 124.2 ± 0.06 | measured |
| Te VIII | 7+ | 143 ± 2.1 | calculated |
| Te IX | 8+ | 167 ± 2.2 | calculated |
| Te X | 9+ | 191.1 ± 2.2 | calculated |
| Te XI | 10+ | 215 ± 2.4 | calculated |
| Te XII | 11+ | 245 ± 2.5 | calculated |
| Te XIII | 12+ | 272 ± 3 | calculated |
| Te XIV | 13+ | 299 ± 3 | calculated |
| Te XV | 14+ | 328 ± 3 | calculated |
| Te XVI | 15+ | 354 ± 3 | calculated |
| Te XVII | 16+ | 461 ± 3 | calculated |
| Te XVIII | 17+ | 491 ± 3 | calculated |
| Te XIX | 18+ | 522 ± 3 | calculated |
| Te XX | 19+ | 555 ± 4 | calculated |
| Te XXI | 20+ | 599 ± 4 | calculated |
| Te XXII | 21+ | 633 ± 4 | calculated |
| Te XXIII | 22+ | 709 ± 4 | calculated |
| Te XXIV | 23+ | 746.12 ± 0.25 | semi-empirical |
| Te XXV | 24+ | 1304 ± 4 | calculated |
| Te XXVI | 25+ | 1377 ± 4 | calculated |
| Te XXVII | 26+ | 1455 ± 4 | calculated |
| Te XXVIII | 27+ | 1538 ± 4 | calculated |
| Te XXIX | 28+ | 1618 ± 4 | calculated |
| Te XXX | 29+ | 1707 ± 4 | calculated |
| Te XXXI | 30+ | 1803 ± 4 | calculated |
| Te XXXII | 31+ | 1889 ± 4 | calculated |
| Te XXXIII | 32+ | 1979 ± 4 | calculated |
| Te XXXIV | 33+ | 2066 ± 5 | calculated |
| Te XXXV | 34+ | 2309 ± 5 | calculated |
| Te XXXVI | 35+ | 2386 ± 5 | calculated |
| Te XXXVII | 36+ | 2472 ± 5 | calculated |
| Te XXXVIII | 37+ | 2552 ± 4 | calculated |
| Te XXXIX | 38+ | 2700 ± 4 | calculated |
| Te XL | 39+ | 2788 ± 4 | calculated |
| Te XLI | 40+ | 2954 ± 4 | calculated |
| Te XLII | 41+ | 3041 ± 0.5 | semi-empirical |
| Te XLIII | 42+ | 7022 ± 4 | calculated |
| Te XLIV | 43+ | 7243 ± 4 | calculated |
| Te XLV | 44+ | 7485 ± 4 | calculated |
| Te XLVI | 45+ | 7714 ± 4 | calculated |
| Te XLVII | 46+ | 8240 ± 4 | calculated |
| Te XLVIII | 47+ | 8499 ± 4 | calculated |
| Te XLIX | 48+ | 8821 ± 4 | calculated |
| Te L | 49+ | 9040.83 ± 0.04 | calculated |
| Te LI | 50+ | 37196.52 ± 0.03 | calculated |
| Te LII | 51+ | 38177.74 ± 0.015 | 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 (42)
| A | N | Half-life | Decay |
|---|---|---|---|
| Te-104 | 52 | < 18 ns | α |
| Te-105 | 53 | 0.63 μs | α |
| Te-106 | 54 | 69 μs | α |
| Te-107 | 55 | 3.6 ms | α |
| Te-108 | 56 | 2.1 s | α |
| Te-109 | 57 | 4.4 s | EC/β⁺ |
| Te-110 | 58 | 18.6 s | EC/β⁺ |
| Te-111 | 59 | 26.2 s | EC/β⁺ |
| Te-112 | 60 | 2.0 min | EC/β⁺ |
| Te-113 | 61 | 1.8 min | EC/β⁺ |
| Te-114 | 62 | 16.4 min | EC/β⁺ |
| Te-115 | 63 | 5.9 min | EC/β⁺ |
| Te-116 | 64 | 2.49 h | EC/β⁺ |
| Te-117 | 65 | 62 min | EC/β⁺ |
| Te-118 | 66 | 6.00 d | EC |
| Te-119 | 67 | 16.05 h | EC/β⁺ |
| Te-120 | 68 | stable | - |
| Te-121 | 69 | 19.27 d | EC/β⁺ |
| Te-122 | 70 | stable | - |
| Te-123 | 71 | stable | - |
| Te-124 | 72 | stable | - |
| Te-125 | 73 | stable | - |
| Te-126 | 74 | stable | - |
| Te-127 | 75 | 9.35 h | β⁻ |
| Te-128 | 76 | 2.34×10²⁴ a | 2β⁻ |
| Te-129 | 77 | 69.5 min | β⁻ |
| Te-130 | 78 | 7.90×10²⁰ a | 2β⁻ |
| Te-131 | 79 | 25.0 min | β⁻ |
| Te-132 | 80 | 3.204 d | β⁻ |
| Te-133 | 81 | 12.5 min | β⁻ |
| Te-134 | 82 | 41.8 min | β⁻ |
| Te-135 | 83 | 19.0 s | β⁻ |
| Te-136 | 84 | 17.66 s | β⁻ |
| Te-137 | 85 | 2.48 s | β⁻ |
| Te-138 | 86 | 1.5 s | β⁻ |
| Te-139 | 87 | 0.72 s | β⁻ |
| Te-140 | 88 | 351 ms | β⁻ |
| Te-141 | 89 | 193 ms | β⁻ |
| Te-142 | 90 | 147 ms | β⁻ |
| Te-143 | 91 | 120 ms | β⁻ |
| Te-144 | 92 | 90 ms | β⁻ |
| Te-145 | 93 | 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