Actinium

Uses

Actinium’s extreme rarity and radioactivity mean it has essentially no industrial or commercial applications, and virtually everything known about it comes from careful laboratory research using tiny quantities. One older application made use of actinium mixed with beryllium as a neutron source, useful in certain scientific instruments and experiments that need a steady, controllable supply of neutrons. More recently, an isotope called actinium-225 has drawn interest as a potential tool in targeted radiation therapy for cancer, where it could be attached to a molecule designed to deliver radiation directly to tumor cells — a promising but still research-stage approach, similar to ongoing work with other rare radioactive elements.

History

Actinium was identified in 1899 by French chemist André-Louis Debierne, who found it in the leftover material from the Curies’ painstaking work separating radium and polonium out of uranium ore. A few years later, German chemist Friedrich Oskar Giesel independently discovered the same element through separate research and initially proposed a different name for it, but Debierne’s earlier work and naming are generally credited as establishing actinium. Its name comes from the Greek word for “ray” or “beam,” a nod to its intense radioactivity, and it went on to lend its name to the entire actinide series of elements that follows it on the periodic table.