Polonium

Polonium is a silvery, intensely radioactive metal. Marie and Pierre Curie discovered it in 1898 while processing tons of uranium ore, and Marie named it after her homeland, Poland. Natural traces exist in uranium ores, but the polonium used today is made in nuclear reactors by bombarding bismuth with neutrons.

Its common form, polonium-210, has a half-life of about 138 days and releases so much energy that a small sample glows and heats itself. That heat kept Soviet moon rovers warm in the 1970s. Its radiation also neutralizes static electricity in brushes and devices used in factories. It is lethally toxic if swallowed or inhaled, as the 2006 poisoning of Alexander Litvinenko in London showed.