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Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra 3 N 2).
Radon-222 (222 Rn, Rn-222, historically radium emanation or radon) is the most stable isotope of radon, with a half-life of approximately 3.8 days. It is transient in the decay chain of primordial uranium-238 and is the immediate decay product of radium-226 .
Toggle the table of contents. List of radioactive nuclides by half-life. ... radium-216: 182 plutonium-239m1: 193 bismuth-203m2: 194 polonium-198m1: 200 polonium-202m
The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). [ 1 ] The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure .
Examples were radium enema treatments, and radium-containing waters to be drunk as tonics. Marie Curie protested against this sort of treatment, warning that "radium is dangerous in untrained hands". [18] Curie later died from aplastic anaemia, likely caused by exposure to ionizing radiation.
In the periodic table published by Dmitri Mendeleev in 1869, ... The decay products of 232 Th include more dangerous radionuclides such as radium and radon.
Radon compounds can be formed by the decay of radium in radium halides, a reaction that has been used to reduce the amount of radon that escapes from targets during irradiation. [24] Additionally, salts of the [RnF] + cation with the anions SbF − 6, TaF − 6, and BiF − 6 are known. [24] Radon is also oxidised by dioxygen difluoride to RnF
Tl is located on the periodic table near two other highly toxic metals, mercury and lead. Tin poisoning from tin metal, its oxides, and its salts are "almost unknown"; on the other hand certain organotin compounds are almost as toxic as cyanide. Such organotin compounds were once widely used as anti-fouling agents. [33]