All practice pages/Interatomic theory/Elements
Element 88, an alkaline earth metal
The glowing element that made the Curies famous, painted onto watch dials until the painters began to fall ill.
Period 7, group 2. The other alkaline earth metals are tinted, and every cell opens its own article.
Two valence electrons, which radium gives up to form the Ra²⁺ ion in its compounds.
Present in uranium ores at about one part in three million of the uranium, as one step in uranium's decay.
Marie and Pierre Curie, working with Gustave Bémont, announced it in December 1898. It took Marie Curie years of processing tons of pitchblende waste to isolate a tenth of a gram of radium chloride in 1902, and she and André-Louis Debierne isolated the metal in 1910. The name comes from the Latin radius, ray.
In the early 1900s radium went into glow-in-the-dark paint for watches and instruments, and into quack tonics and cosmetics. Dial painters who shaped their brushes with their lips, the Radium Girls, developed bone cancers, and their lawsuits changed workplace safety law. Today radium-223 treats prostate cancer that has spread to the bones.
Radioactive, and stored by the body in bone as if it were calcium, where it causes cancer. The curie, a unit of radioactivity, was originally based on one gram of radium-226.