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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).
The longest half-lives among them are 1.387 million years for beryllium-10, 99.4 thousand years for calcium-41, 1599 years for radium-226 (radium's longest-lived isotope), 28.90 years for strontium-90, 10.51 years for barium-133, and 5.75 years for radium-228. All others have half-lives of less than half a year, most significantly shorter.
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 ...
This named isotope later became the official name for element 88. RaA: Radium A: 84: From radium and A. Placeholder name given at one time to 218 Po, an isotope of polonium identified in the decay chain of radium. RaB: Radium B: 82: From radium and B. Placeholder name given at one time to 214 Pb, an isotope of lead identified in the decay chain ...
The Americans also wished to name element 106 seaborgium. This naming dispute ran from the 1970s (when the elements were discovered) to the 1990s, when the International Union of Pure and Applied Chemistry (IUPAC) created a tentative list of the element names for elements 104 to 109. The Americans, however, refused to agree with these names ...
41 of the 118 known elements have names associated with, or specifically named for, places around the world or among astronomical objects. 32 of these have names tied to the places on Earth, and the other nine are named after to Solar System objects: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium after their respective ...
In particular, he studied the product in the uranium series, radon-222, which he called radium emanation. [6] In the early 20th century, the element radon was known by several different names. Chemist William Ramsay, who extensively studied the element's chemical properties, suggested the name niton, and Rutherford originally suggested emanation.
When it was realized that all of these are isotopes of the same element, many of these names fell out of use, and "radium" came to refer to all isotopes, not just 226 Ra, [5] though mesothorium 1 in particular was still used for some time, with a footnote explaining that it referred to 228 Ra. [6] Some of radium-226's decay products received ...