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Polonium is a chemical element; it has symbol Po and atomic number 84. A rare and highly radioactive metal (although sometimes classified as a metalloid ) with no stable isotopes , polonium is a chalcogen and chemically similar to selenium and tellurium , though its metallic character resembles that of its horizontal neighbors in the periodic ...
The implosion design of "Gadget", as the Trinity device was codenamed, used conventional explosive lenses to compress a sphere of plutonium into a supercritical mass, which was simultaneously showered with neutrons from "Urchin", an initiator made of polonium and beryllium (neutron source: (α, n) reaction). [42]
The symbol Po is now used for polonium. [nb 1] Pp: Philippium: 67: Delafontaine discovered a new element and named it philippium. Per Teodor Cleve isolated it and renamed it holmium. [7] R: Rhodium: 45: Current symbol is Rh. (The symbol is now sometimes used for an alkyl group.) [nb 1] Rd: Radium: 88: Current symbol is Ra. [nb 1] Rf ...
Polonium-210 (210 Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206 Pb with a half-life of 138.376 days (about 4 + 1 ⁄ 2 months), the longest half-life of all naturally occurring polonium isotopes ( 210–218 Po). [ 1 ]
A synthetic element is one of 24 known chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made".
The melting and boiling points of livermorium are expected to continue the trends down the chalcogens; thus livermorium should melt at a higher temperature than polonium, but boil at a lower temperature. [3] It should also be denser than polonium (α-Lv: 12.9 g/cm 3; α-Po: 9.2 g/cm 3); like polonium it should also form an α and a β allotrope.
Chemical compounds are substances made of ... and are therefore considered transient elements. Of these 11 transient elements, five (polonium ... and Symbol all serve ...
Polonium can also be produced by high neutron fluxes in nuclear reactors. Approximately 100 grams of polonium are produced yearly. [65] All the polonium produced for commercial purposes is made in the Ozersk nuclear reactor in Russia. From there, it is taken to Samara, Russia for purification, and from there to St. Petersburg for distribution ...