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
Well-formed element end of the "opening" (only) tag, e.g. , , , etc. In HTML 4.01 and earlier, no slash is added to terminate the element. HTML5 does not require one, but it is often added for compatibility with XHTML and XML processing. In a well-formed document, For example, the code below is not well-formed HTML, because the codice_3 and codice_4 elements overlap: In XML, the phrase "well-formed document" is often used to describe a text that follows all the syntactic rules as well-formedness rules in the XML specification: strictly speaking the phrase is tautological, since a text that does not follow