User:R8R/Radium
Chemical element, symbol Ra and atomic number 88 / From Wikipedia, the free encyclopedia
Radium (/ˈreɪdiəm/ RAY-dee-əm) is a chemical element with atomic number 88, represented by symbol Ra. It is an almost pure white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope of radium-226, which has a half-life of 1601 years and decays into radon gas. Due to such instability, radium is luminescent; it gives off a faint blue color.
Radium was discovered by Marie Skłodowska-Curie and Pierre Curie in 1898 in uraninite sample in form of radium chloride, publishing results of their research to French Academy of Sciences five days after the discovery. Radium was isolated in its metallic state by Curie and André-Louis Debierne through the electrolysis of a pure radium chloride in 1910. Since its discovery, it has given names like radium A and radium C2 to several isotopes of other elements that are decay products of radium-226.
In nature, radium is found in trace amounts in uranium ores in a very low quantity, as low as a gram per seven tonnes of uraninite. It is not incorporated into biochemical processes nor necessary or for life, being very dangerous due to high instability of its isotopes and chemical reactivity.