Element: Antimony
General data
| Element name | Antimony |
|---|---|
| Chemical symbol | Sb |
| Atomic number Z | 51 |
| Year discovered | known since antiquity |
| Standard state (25°C) | Solid |
| Category | Metalloid |
| Block | p |
| Atomic mass | 121.76 |
| CPK color | #9E63B5 |
Physical properties
| Melting point | 903.78 K (630.63 °C) |
|---|---|
| Boiling point | 1860 K (1587 °C) |
| Density | 6.685 g/cm³ |
Energy properties
| First ionization energy | 8.64 eV |
|---|---|
| Electron affinity | 1.07 eV |
Atomic structure
| Protons | 51 (Atomic number) |
|---|---|
| Neutrons (Sb-121, most abundant isotope) | 70 |
| Electrons | 51 |
| Electron configuration | [Kr] 5s² 4d¹⁰ 5p³ |
| Oxidation states | +5, +3, -3 |
| Electronegativity (Pauling) | 2.05 |
| Atomic radius (van der Waals) | 206 pm |
Ionization energies - NIST ASD (51 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Sb I | 0+ | 8.608389 ± 0.000012 | measured |
| Sb II | 1+ | 16.626 ± 0.025 | measured |
| Sb III | 2+ | 25.3235 | measured |
| Sb IV | 3+ | 43.804 ± 0.025 | measured |
| Sb V | 4+ | 55 ± 0.1 | semi-empirical |
| Sb VI | 5+ | 99.51 ± 0.05 | measured |
| Sb VII | 6+ | 117 ± 2 | calculated |
| Sb VIII | 7+ | 139 ± 2.1 | calculated |
| Sb IX | 8+ | 162 ± 2.2 | calculated |
| Sb X | 9+ | 185 ± 2.2 | calculated |
| Sb XI | 10+ | 214 ± 2.4 | calculated |
| Sb XII | 11+ | 238 ± 2.5 | calculated |
| Sb XIII | 12+ | 265 ± 3 | calculated |
| Sb XIV | 13+ | 292 ± 3 | calculated |
| Sb XV | 14+ | 317 ± 3 | calculated |
| Sb XVI | 15+ | 420 ± 3 | calculated |
| Sb XVII | 16+ | 447 ± 3 | calculated |
| Sb XVIII | 17+ | 479 ± 3 | calculated |
| Sb XIX | 18+ | 510 ± 3 | calculated |
| Sb XX | 19+ | 552 ± 4 | calculated |
| Sb XXI | 20+ | 584 ± 4 | calculated |
| Sb XXII | 21+ | 657 ± 4 | calculated |
| Sb XXIII | 22+ | 693.26 ± 0.24 | semi-empirical |
| Sb XXIV | 23+ | 1214 ± 4 | calculated |
| Sb XXV | 24+ | 1285 ± 4 | calculated |
| Sb XXVI | 25+ | 1360 ± 4 | calculated |
| Sb XXVII | 26+ | 1441 ± 4 | calculated |
| Sb XXVIII | 27+ | 1518 ± 4 | calculated |
| Sb XXIX | 28+ | 1606 ± 4 | calculated |
| Sb XXX | 29+ | 1698 ± 4 | calculated |
| Sb XXXI | 30+ | 1781 ± 4 | calculated |
| Sb XXXII | 31+ | 1869 ± 4 | calculated |
| Sb XXXIII | 32+ | 1954 ± 4 | calculated |
| Sb XXXIV | 33+ | 2190 ± 5 | calculated |
| Sb XXXV | 34+ | 2266 ± 5 | calculated |
| Sb XXXVI | 35+ | 2349 ± 5 | calculated |
| Sb XXXVII | 36+ | 2428 ± 5 | calculated |
| Sb XXXVIII | 37+ | 2567 ± 4 | calculated |
| Sb XXXIX | 38+ | 2654 ± 4 | calculated |
| Sb XL | 39+ | 2815 ± 4 | calculated |
| Sb XLI | 40+ | 2900 ± 0.5 | semi-empirical |
| Sb XLII | 41+ | 6714 ± 4 | calculated |
| Sb XLIII | 42+ | 6929 ± 4 | calculated |
| Sb XLIV | 43+ | 7167 ± 4 | calculated |
| Sb XLV | 44+ | 7390 ± 4 | calculated |
| Sb XLVI | 45+ | 7887 ± 4 | calculated |
| Sb XLVII | 46+ | 8140 ± 4 | calculated |
| Sb XLVIII | 47+ | 8455 ± 4 | calculated |
| Sb XLIX | 48+ | 8669.48 ± 0.04 | calculated |
| Sb L | 49+ | 35710.03 ± 0.025 | calculated |
| Sb LI | 50+ | 36668.183 ± 0.012 | 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 (39)
| A | N | Half-life | Decay |
|---|---|---|---|
| Sb-104 | 53 | 0.49 s | EC/β⁺ |
| Sb-105 | 54 | 1.12 s | EC/β⁺ |
| Sb-106 | 55 | 0.6 s | EC/β⁺ |
| Sb-107 | 56 | 4.0 s | EC/β⁺ |
| Sb-108 | 57 | 7.4 s | EC/β⁺ |
| Sb-109 | 58 | 17.2 s | EC/β⁺ |
| Sb-110 | 59 | 23.6 s | EC/β⁺ |
| Sb-111 | 60 | 74.9 s | EC/β⁺ |
| Sb-112 | 61 | 53.6 s | EC/β⁺ |
| Sb-113 | 62 | 6.67 min | EC/β⁺ |
| Sb-114 | 63 | 3.49 min | EC/β⁺ |
| Sb-115 | 64 | 32.0 min | EC/β⁺ |
| Sb-116 | 65 | 15.8 min | EC/β⁺ |
| Sb-117 | 66 | 2.80 h | EC/β⁺ |
| Sb-118 | 67 | 3.6 min | EC/β⁺ |
| Sb-119 | 68 | 38.2 h | EC |
| Sb-120 | 69 | 15.89 min | EC/β⁺ |
| Sb-121 | 70 | stable | - |
| Sb-122 | 71 | 2.6941 d | β⁻ |
| Sb-123 | 72 | stable | - |
| Sb-124 | 73 | 60.209 d | β⁻ |
| Sb-125 | 74 | 2.7577 a | β⁻ |
| Sb-126 | 75 | 12.3 d | β⁻ |
| Sb-127 | 76 | 3.84 d | β⁻ |
| Sb-128 | 77 | 9.05 h | β⁻ |
| Sb-129 | 78 | 4.40 h | β⁻ |
| Sb-130 | 79 | 40.5 min | β⁻ |
| Sb-131 | 80 | 23.03 min | β⁻ |
| Sb-132 | 81 | 2.79 min | β⁻ |
| Sb-133 | 82 | 2.41 min | β⁻ |
| Sb-134 | 83 | 675 ms | β⁻ |
| Sb-135 | 84 | 1.668 s | β⁻ |
| Sb-136 | 85 | 924 ms | β⁻ |
| Sb-137 | 86 | 506 ms | β⁻ |
| Sb-138 | 87 | 314 ms | β⁻ |
| Sb-139 | 88 | 182 ms | β⁻ |
| Sb-140 | 89 | 171 ms | β⁻ |
| Sb-141 | 90 | 100 ms | β⁻ |
| Sb-142 | 91 | 50 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