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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".
These chemical elements are usually synthetically prepared. Most cannot be found in nature. Most cannot be found in nature. Although technetium , promethium , astatine , neptunium , and plutonium do occur in nature, they are very rare and were all discovered by synthesis.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
World Book Encyclopedia, Exploring Earth. HyperPhysics, Georgia State University, Abundance of Elements in Earth's Crust. Eric Scerri, The Periodic Table, Its Story and Its Significance, Oxford University Press, 2007 "EarthRef.org Digital Archive (ERDA) -- Major Element Composition of the Core vs the Bulk Earth". earthref.org
Bureaucratium is an element with a negative half-life, becoming more massive and sluggish as time goes by. Byzanium Raise the Titanic! [29] Fictional element in the book Raise the Titanic! and its film adaptation, which is a main focus of the story arc. It is a powerful radioactive material sought by both the Americans and Russians for use as ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Pages in category "Artificial objects" The following 7 pages are in this category, out of 7 total. This list may not reflect recent changes. A. Anthroposphere;
This is a partial list of artificial objects left on extraterrestrial surfaces. Artificial objects on Venus. Artificial objects on the Moon. Artificial objects on ...