Silver is a chemical element with the symbol Ag and atomic number 47. It is a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth’s crust in the pure, free elemental form (“native silver”), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most Ag is produced as a byproduct of copper, gold, lead, and zinc refining.
It’s purity is typically measured on a per-mille basis; a 94%-pure alloy is described as “0.940 fine”. As one of the seven metals of antiquity, silver has had an enduring role in most human cultures.
Characteristics of Silver
- It is an extremely soft, ductile and malleable transition metal, though it is slightly less malleable than gold. Ag crystallizes in a face-centered cubic lattice with bulk coordination number 12, where only the single 5s electron is delocalized, similarly to copper and gold.
- It has a brilliant white metallic luster that can take a high polish, and which is so characteristic that the name of the metal itself has become a colour name.
- Unlike copper and gold, the energy required to excite an electron from the filled d band to the s-p conduction band in silver is large enough (around 385 kJ/mol) that it no longer corresponds to absorption in the visible region of the spectrum, but rather in the ultraviolet; hence Ag is not a coloured metal.
- It readily forms alloys with copper and gold, as well as zinc. Zinc-silver alloys with low zinc concentration may be considered as face-centred cubic solid solutions of zinc in silver, as the structure of the silver is largely unchanged while the electron concentration rises as more zinc is added.