Search results
Results from the WOW.Com Content Network
Francium-223 is the most stable isotope, with a half-life of 21.8 minutes, [8] and it is highly unlikely that an isotope of francium with a longer half-life will ever be discovered or synthesized. [22] Francium-223 is a fifth product of the uranium-235 decay series as a daughter isotope of actinium-227; thorium-227 is the more common daughter. [23]
This is the list of extremely hazardous substances defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. § 11002).The list can be found as an appendix to 40 CFR 355. [1]
This page lists radioactive nuclides by their half-life.
All of the discovered alkali metals occur in nature as their compounds: in order of abundance, sodium is the most abundant, followed by potassium, lithium, rubidium, caesium, and finally francium, which is very rare due to its extremely high radioactivity; francium occurs only in minute traces in nature as an intermediate step in some obscure ...
Francium compounds are compounds containing the element francium (Fr). Due to francium being very unstable, its salts are only known to a small extent. Francium coprecipitates with several caesium salts, such as caesium perchlorate, which results in small amounts of francium perchlorate.
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".
However, it would appear that francium perchlorate has been formed, as it coprecipitates with caesium perchlorate, and several other insoluble francium salts are similarly known (Hyde, E.K., Radiochemical Methods for the Isolation of Element 87 (Francium), J. Am. Chem. Soc., 1952, 74, 4181) The article also quotes a value for the Pauling ...
Perey named the element francium, after her home country, and it joined the other alkali metals in Group 1 of the periodic table of elements. [3] [7] Francium is the second rarest element (after astatine) — only about 550g exists in the entire Earth's crust at any given time — and it was the last element to be discovered in nature.