Tellurium: Difference between revisions

Tellurium has two [[allotrope]]s, crystalline and amorphous. When [[crystal]]line, tellurium is silvery-white with a metallic luster. The crystals are [[trigonal crystal system|trigonal]] and [[chiral]] ([[space group]] 152 or 154 depending on the chirality), like the gray form of [[selenium]]. It is a brittle and easily pulverized metalloid. Amorphous tellurium is a black-brown powder prepared by precipitating it from a solution of [[tellurous acid]] or [[telluric acid]] (Te(OH)₆).<ref name="lan" /> Tellurium is a [[semiconductor]] that shows greater electrical conductivity in certain directions depending on [[atom]]ic alignment<ref>{{Cite web |title=Tellurium (Te) {{!}} AMERICAN ELEMENTS ® |url=https://www.americanelements.com/tellurium.html |access-date=2024-07-19 |website=American Elements: The Materials Science Company |language=en}}</ref>; the conductivity increases slightly when exposed to light ([[photoconductivity]]).<ref>{{Cite book|chapter-url = https://books.google.com/books?id=Ty5Ymlg_Mh0C&pg=PA89|pages = 89–91|isbn = 978-0-8493-8912-2|chapter = Tellurium|publisher = CRC Press|title = Semiconductor materials|first = Lev Isaakovich|last = Berger|date = 1997|url = https://archive.org/details/semiconductormat0000berg/page/89}}</ref> When molten, tellurium is corrosive to copper, [[iron]], and [[stainless steel]]. Of the [[chalcogen]]s (oxygen-family elements), tellurium has the highest melting and boiling points, at {{convert|722.66|and|1261|K|°C}}, respectively.<ref>[http://www.ptable.com/#Property/State Periodic Table]. ptable.com</ref>