radium
/ˈreɪdiəm/
noun
- A highly radioactive, silvery-white metal that was once used in luminous paints and medical treatments. It is now handled with extreme care due to its dangerous radiation.
- Because radium is so dangerous, it is now stored in special lead containers.
- Old watch dials were sometimes painted with radium to make them glow in the dark.
- Marie Curie discovered radium and won a Nobel Prize for her work.