Editing Period 5 element (section)

===Tellurium===
{{main|Tellurium}}
'''Tellurium''' is a [[chemical element]] that has the symbol '''Te''' and [[atomic number]] 52. A brittle, mildly toxic, rare, silver-white [[metalloid]] which looks similar to [[tin]], tellurium is chemically related to [[selenium]] and [[sulfur]]. It is occasionally found in native form, as elemental crystals. Tellurium is far more common in the universe than on Earth. Its extreme [[abundance of the chemical elements|rarity]] in the Earth's crust, comparable to that of [[platinum]], is partly due to its high atomic number, but also due to its formation of a volatile [[hydride]] which caused the element to be lost to space as a gas during the hot nebular formation of the planet.

Tellurium was discovered in [[Transylvania]] (today part of [[Romania]]) in 1782 by [[Franz-Joseph Müller von Reichenstein]] in a mineral containing tellurium and [[gold]]. [[Martin Heinrich Klaproth]] named the new element in 1798 after the Latin word for "earth", ''tellus''. Gold telluride minerals (responsible for the name of [[Telluride, Colorado]]) are the most notable natural gold compounds. However, they are not a commercially significant source of tellurium itself, which is normally extracted as by-product of [[copper]] and [[lead]] production.

Tellurium is commercially primarily used in [[alloy]]s, foremost in steel and copper to improve machinability. Applications in [[Photovoltaic module|solar panels]] and as a [[semiconductor]] material also consume a considerable fraction of tellurium production.