|
|||||||
|
|
|
|||||
|
|
|||||||
Sb
Sb at. wt. 121.75
at. no. 51
m.p. 630.74°C
b.p. 1750°C
sp. gr. 6.691 (20°C)
valence 0, -3, +3, or +5.
| SHELL | K | L | M | N | O | P | Q |
| SUB SHELL | He | Neon | Argon | Krypton | Xenon | Radon | Eka-radon |
| 1s | 2s 2p | 3s 3p | 3d 4s 4p | 4d 5s 5p | 4f 5d 6s 6p | 5f 6d 7s 7p | |
| Antimony | 1s22s22p63s23p63d104s24p64d105s25p3 | ||||||
| Symbol | 4S3/2 | ||||||
Antimony was recognized in compounds by the ancients and was known as a metal at the beginning Of the 17th century and possibly much earlier. It is not abundant, but is found in over 100 mineral species. It is sometimes found native, but more frequently as the'sulfide, stibnite (5b253); it is also found as antimonides of the heavy metals, and as oxides. It is ex- tracted from the sulfide by roasting to the oxide, which is reduced by salt and scrap iron; from its oxides it is also prepared by reduction with carbon. Two allotropic forms of antimony exist: the normal stable, metallic forrn, and the amorphous gray form. The socalled explosive antimony is an ill-defined material always containing an appreciable amount of halogen; therefore it no longer warrants consider- ation as a separate allotrope. The yellow form, obtained by oxidation of stibine, SbH3, is probably impure, and is not a distinct form. Metallic antimony is an extremely brittle metal of a flaky, crystalline texture. It is bluish-white and has a metallic luster. It is not acted on by air at room temperature, but burns brilliantly when heated with th? formation of white fumes of 5b203. It is a poor conductor of heat and electricity, and has a hardness of 3 to 3.5. Antimony, avail- able commercially with a purity of 99.999 + %, is finding use in semiconductor technology, for making infrared detectors, diodes, and Hall-effect devices. Commercial- grade antimony is widely used in alloys with percentages ranging from one to twenty. It greatly increases the hardness and mechanical strength of lead. Batteries, antifriction alloys, type metal, cable sheathing, and minor products use about half the metal produced. Compounds taking up the other half are oxides, sulfides, sodium antimonate, and antimony trichloride. These are used in manufacturing flame-proofing compounds, paints, ceramic enamels, glass and.pottery. Tartar emetic (hydrated potassium antimonyl- tartate) is used as a medicine. Antimony and many of its compounds are toxic. The maximum allowable concentra- tion of antimony dust in the air is recommended to be 0.5 mg/cubic meter. Atmospheric concentrations of stibine should not exceed 0.1 ppm.
Return to periodic table
| |
| |
