Antimony is a chemical element with symbol Sb and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite. Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name, kohl
History and Discovery
Antimony has been known since ancient times. It was used for cosmetic and medicinal purposes in its powdered form. In Arabic language, it was named kohl. It was named antimonium in late Greek language. And was given the name antimoine in French which mean “monk-killer” as in early days the alchemists were monks, and antimony was poisonous [1]. The earliest description of this element was presented by Vannoccio Biringuccio in 1540. Its symbol is Sb, which was given by Jakob Berzelius as an abbreviation for stibium [2].
Antimony
| Periodic Table Classification | Group 15 Period 5 |
|---|---|
| State at 20C | Solid |
| Color | Silvery lustrous gray |
| Electron Configuration | [Kr] 4d10 5s2 5p3 |
| Electron Number | 51 |
| Proton Number | 51 |
| Electron Shell | 2, 8, 18, 18, 5 |
| Density | 6.68 g.cm-3 at 20°C |
| Atomic number | 51 |
| Atomic Mass | 121.76 g.mol -1 |
| Electronegativity according to Pauling | 2.05 |
Occurrence
Antimony is not very abundant element. It is present in around 0.5 ppm [3]. In nature, it is present in the form of mineral, such as stibnite, which is its sulfide mineral (Sb2S3). Antimony is found in more than 100 types of minerals. In early days, China was the biggest producer of antimony, which supply around 84% of the world share. Other countries that have reservoirs of antimony include Tajikistan, Russia, South Africa and Bolivia.
Physical Characteristics
Antimony is a shiny grey metalloid. It is a soft element and cannot be used to make hard objects, including coins. There are four allotropic forms of antimony three metastable forms: yellow, black and explosive, and one metallic form that is stable.
Chemical Characteristics
At room temperature, antimony does not react with air, but when heated it reacts with oxygen to produce antimony trioxide. It does not react with acids. The most commo and stable oxidation state of antimony is +5. Antimony reacts with halogens and form halides with +3 and +5 oxidation states. It reacts with metals, such as silver and indium to form silver antimonide and indium antimonide.
Significance and Uses
- Antimony is used to make flame retardant compounds.
- Antimony is used to make useful alloys to increase mechanical strength and hardness. For instance, it is used in alloying of lead that is used in acid batteries to improve charging features.
- Antimony is used to make lead shot, bullets, electrical cables, and solders.
- Antimony is used as a catalyst in industrial processes.
- Antimony is used to make pigments.
- It is used as a fining agent to remove bubbles from glass, especially in TV and laptop screens.
- Antimony compounds are used in some drugs and veterinary medications.
Health Hazards
Antimony in its pure or elemental form is non-toxic. However, some compounds of antimony are toxic and are considered carcinogens. For instance, antimony trioxide in powdered form can lead to irritation of nose and throat when inhaled and can cause cancer. Prolonged dermal exposure to antimony dust can lead to damage and infection of the skin. A dose of 50mg/m3 of antimony is fatal for humans. In powdered form, antimony is explosive and can lead to spontaneous ignition when exposed to air.
Isotopes of Antimony
It has two stable isotopes, antimony-121 and antimony-123. These isotopes have almost same natural abundance, 57.36% (Sb-121) and 42.64% (Sb-123). There are thirty-five radioactive isotopes of antimony, and among them the most stable isotope is antimony-125 that has a half life of 2.75 years.
REFERENCES
[1]. Harper, Douglas. “antimony”. Online Etymology Dictionary.
[2]. In his long article on chemical reactions and nomenclature – Jöns Jacob Berzelius, “Essay on the cause of chemical proportions, and on some circumstances relating to them: together with a short and easy method of expressing them,” Annals of Philosophy, vol. 2, pages 443–454 (1813) and vol. 3, pages 51–62, 93–106, 244–255, 353–364 (1814) – on page 52, Berzelius lists the symbol for antimony as “St”; however, starting on page 248, Berzelius subsequently uses the symbol “Sb” for antimony
[3]. “Mineral Commodity Summaries: Antimony” (PDF). United States Geological Survey. Retrieved 1 January 2016.