Precious metal

A precious metal is a rare, naturally occurring metallic chemical element of high economic value. Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial commodities. Gold, silver, platinum, and palladium each have an ISO 4217 currency code.

The best-known precious metals are the coinage metals, gold and silver. Although both have industrial uses, they are better known for their uses in art, jewellery, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded much higher prices than common industrial metals.

Metal

A metal (from Greek μέταλλον métallon, "mine, quarry, metal") is a material (an element, compound, or alloy) that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable — that is, they can be hammered or pressed permanently out of shape without breaking or cracking — as well as fusible (able to be fused or melted) and ductile (able to be drawn out into a thin wire). About 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms.

Astrophysicists use the term "metal" to collectively describe all elements other than hydrogen and helium. Thus, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium.

Many elements and compounds that are not normally classified as metals become metallic under high pressures; these are formed as metallic allotropes of non-metals.

Structure and bonding

Metals (album)

Metals is the fourth studio album by Canadian singer-songwriter Feist. It was released on September 30, 2011 in Ireland, Austria, Switzerland, Germany, Sweden and Belgium; October 3, 2011 in the United Kingdom; and October 4, 2011 in the United States and Canada. The first single from the album is "How Come You Never Go There", which was released on August 12, 2011. The album was supported by a world tour which started in Amsterdam, Netherlands on October 15, 2011 and finished on October 20, 2012 in Latin America.

Metals debuted on the US Billboard 200 at number 7, and sold 38,000 copies in its first week. It earned Feist's best sales week and it was her first top 10 chart in the US. The album received acclaim from critics.

Promotion

Promotion for the album began with short videos which feature snippets of tracks and the making of the album. They were posted on her website and other social networking sites since July 21, 2011. Four days after, she officially announced the release of Metals. Artwork for the album was revealed on August 2, 2011, previously fans were given the opportunity to select the color design for the album cover on Facebook.

Metallicity

In astronomy and physical cosmology, the metallicity or Z is the fraction of mass of a star or other kind of astronomical object that is not in hydrogen (X) or helium (Y). Most of the physical matter in the universe is in the form of hydrogen and helium, so astronomers use the word "metals" as a convenient short term for "all elements except hydrogen and helium". This usage is distinct from the usual physical definition of a solid metal. The astronomical usage is claimed to be justified because in the high-temperature and pressure environment of a star, atoms do not undergo chemical reactions and effectively have no chemical properties, including that of being a metal as usually understood. For example, stars and nebulae with relatively high abundances of carbon, nitrogen, oxygen, and neon are called "metal-rich" in astrophysical terms, even though those elements are non-metals in chemistry.

The distinction between hydrogen and helium on the one hand and metals on the other is relevant because the primordial universe is believed to have contained virtually no metals, which were later synthesised within stars.