Antimony is a chemical element wi symbol Sb (frae Laitin : stibium ) an atomic nummer 51. A lustrous gray metalloid , it is fand in naitur mainly as the sulfide mineral stibnite (Sb2 S3 ). Antimony compoonds hae been kent syne auncient times an wis uised for cosmetics; metallic antimony wis kent an aa, but it wis erroneously identified as leid . It wis established tae be an element aroond the 17t century.
Antimony, 51 Antimony Pronunciation Appearance sillery lustrous gray Standard atomic weight A r, std (Sb) 7002121760000000000♠ 121.760(1)[1] Antimony in the periodic cairt Atomic nummer (Z ) 51 Group group 15 (pnictogens) Period period 5 Block p-block Element category Metalloid Electron confeeguration [Kr] 4d10 5s2 5p3 Electrons per shell 2, 8, 18, 18, 5 Pheesical properties Phase at STP solit Meltin pynt 903.78 K (630.63 °C, 1167.13 °F) Bylin pynt 1860 K (1587 °C, 2889 °F) Density (near r.t. ) 6.697 g/cm3 when liquid (at m.p. ) 6.53 g/cm3 Heat o fusion 19.79 kJ/mol Heat o vapourisation 193.43 kJ/mol Molar heat capacity 25.23 J/(mol·K) Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 807 876 1011 1219 1491 1858
Atomic properties Oxidation states −3 [2] +3 +5 Electronegativity Pauling scale: 2.05 Ionisation energies Atomic radius empirical: 140 pm Covalent radius 139±5 pm Van der Waals radius 206 pm Colour lines in a spectral range Spectral lines o antimony Ither properties Naitural occurrence primordial Creestal structur trigonal Speed o soond thin rod 3420 m/s (at 20 °C) Thermal expansion 11 µm/(m·K) (at 25 °C) Thermal conductivity 24.4 W/(m·K) Electrical resistivity 417 n Ω·m (at 20 °C) Magnetic orderin diamagnetic[3] Young's modulus 55 GPa Shear modulus 20 GPa Bulk modulus 42 GPa Mohs haurdness 3.0 Brinell haurdness 294 MPa CAS Nummer 7440-36-0 History Diskivery 3000 BC First isolation Vannoccio Biringuccio (1540) Main isotopes o antimony Decay modes in parentheses are predictit, but hae nae yet been observed | references
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