Period 5 element other metal is not easily oxidized in air and is used to coat other metals to prevent corrosion. The firstalloy, used in 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 tableware from the Bronze Age until the 20th century. In modern times tin is used in many alloys, most notably tin/lead soft solders, typically containing 60% or more of tin. Another large application for tin is
Post-transition metal sulfide (AsS). Arsenic forms a series of anionic arsenates such as NaAsO and PbHAsO, and Zintl phases such as NaAs, CaAs and SrAs. Antimony is a soft (MH 3.0) and brittle semi-metallic element. It is commonly regarded as a metalloid, or by some other authors as either a metal or a non-metal. It exhibits poor electrical conductivity which, like a metal, decreases with temperature. It has a relatively open and partially covalent crystalline structure (BCN 3+3). Antimony forms covalent bonds with most other elements. The oxide in its preferred oxidation state (SbO, +3) is amphoteric. Antimony forms a series of