Silver

Silver is a very ductile and malleable (slightly harder than gold) univalent coinage metal with a brilliant white metallic luster that can take a high degree of polish. It has the highest electrical conductivity of all metals, even higher than copper, but its greater cost and tarnishability has prevented it from being widely used in place of copper for electrical purposes, though it was used in the electromagnets used for enriching uranium during World War II (mainly because of the wartime shortage of copper).

Pure silver has the highest thermal conductivity, whitest color, the highest optical reflectivity, although aluminium slightly outdoes it in parts of the visible spectrum, and is a poor reflector of ultraviolet light. Silver also has the lowest contact resistance of any metal. Silver halides are photosensitive and are remarkable for the effect of light upon them. This metal is stable in pure air and water, but does tarnish when it is exposed to ozone, hydrogen sulfide, or air containing sulfur. The most common oxidation state of silver is +1 (for example, silver nitrate, AgNO₃); a few +2 (for example, silver(II) fluoride; AgF₂) and +3 compounds (for example, silver(III) persulfate; Ag₂(SO₅)₃) are also known.

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