Tin
Tin is a chemical element with the symbol Sn (for Latin: stannum) and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows a chemical similarity to both neighboring group-14 elements, germanium and lead, and has two possible oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stableisotopes in the periodic table. It is a silvery, malleable other metal that is not easily oxidized in air, obtained chiefly from the mineral cassiterite where it occurs as tin dioxide, SnO2.
The first alloy used on a large scale since 3000 BC was bronze, an alloy of tin and copper. After 600 BC, pure metallic tin was produced. Pewter, which is an alloy of 85–90% tin with the remainder commonly consisting of copper, antimony and lead, was used for flatware from the Bronze Age until the 20th century. In modern times, tin is used in many alloys, most notably tin/lead soft solders, which are typically 60% or more tin. Another large application for tin is corrosion-resistant tin plating of steel. Because of its low toxicity, tin-plated metal was used for food packaging as tin cans, which are now made mostly of steel,[citation needed] even though the name is kept in English.
ليست هناك تعليقات:
إرسال تعليق