Antimony (Sb)


  • Symbol: Sb
  • Atomic Number: 51
  • Atomic Weight: 121.760
  • Element Classification: Metalloid
  • Discovered By: Known to ancient civilizations
  • Discovery Date: Known since ancient times
  • Name Origin: From the Greek ‘anti’ and ‘monos’ (not alone), or Latin ‘antimonium’
  • Density(g/cc): 6.697
  • Melting Point: 630.63°C
  • Boiling Point: 1587°C
  • Appearance: Silvery, lustrous gray
  • Atomic Radius(pm): 133


Antimony was known to ancient civilizations and used in cosmetics and medicines as far back as 3000 BC. The exact date of discovery is not known due to its early use. The name antimony is derived from the Greek words ‘anti’ and ‘monos’, meaning “not alone”, which might refer to its rare occurrence as a pure element, or from the Latin ‘antimonium’, used by alchemists. The symbol Sb comes from the mineral stibnite (antimony sulfide, Sb₂S₃), from which antimony was commonly obtained, and is derived from the Latin ‘stibium’.

Relation to Other Elements

Antimony is classified as a metalloid because it has properties that are intermediate between metals and nonmetals. It shares a group with nitrogen, phosphorus, arsenic, and bismuth in the periodic table. Antimony resembles arsenic in its brittle, metallic appearance but is less toxic and exhibits greater stability at high temperatures. It commonly exhibits oxidation states of +3 and +5 in its compounds.

Natural Occurrence

Antimony is not found in nature as a free metal, but rather in various minerals, with stibnite (Sb₂S₃) being the most significant source. Other antimony-bearing minerals include valentinite (Sb₂O₃) and kermesite (Sb₂S₂O). Major reserves of antimony are found in China, Russia, Bolivia, and South Africa.


Antimony has several important applications:

  • Flame Retardants: The largest use of antimony is as a flame retardant in plastics, textiles, and building materials. Antimony trioxide (Sb₂O₃) is used as a synergist to enhance the efficacy of halogenated flame retardants.
  • Lead-Acid Batteries: Antimony is used in lead-acid batteries as an alloying agent with lead to increase the strength and hardness of the lead, improving battery life and performance.
  • Alloys: Antimony is alloyed with lead to be used in solder, type metal, and bearing metal. Antimony alloys have low friction and high hardness, making them suitable for various applications.
  • Chemicals: Antimony compounds, especially antimony trisulfide, are used in the production of fireworks, safety matches, and military applications.
  • Medicine: Antimony compounds have historical and limited contemporary use in treatments for parasitic infections, such as leishmaniasis.

The historical and modern uses of antimony reflect its versatility as both a metal and a nonmetal. Despite its toxicity in certain forms, antimony remains an important material in flame retardants, alloys, and various chemical applications, illustrating the dual nature of metalloids in technology and industry.


Tin (Sn)

Tellurium (Te)