radium

noun

ra·​di·​um ˈrā-dē-əm 

often attributive

: an intensely radioactive metallic chemical element that occurs in combination in minute quantities in minerals (such as pitchblende or carnotite), emits alpha particles and gamma rays to form radon, and is used chiefly in the treatment of cancer and in radiographic devices see Chemical Elements Table

Examples of radium in a Sentence

Recent Examples on the Web

Eventually, in light of the dangers of radium, Panerai revamped its lume with a new material called Luminor. —Cait Bazemore, Robb Report, 31 Oct. 2024

The double Nobel Prize winner is most famous for her discovery of radioactivity, as well as the radioactive elements radium and polonium. —Clara Moskowitz, Scientific American, 15 Oct. 2024

Both radium and radon are radioactive and can cause cancer. —Shawn Tully, Fortune, 9 Oct. 2024

The hands and indexes are delicately filled with egg-shell colored Super-LumiNova, reflecting the radium originally used, ensuring visibility in all lighting conditions. —Bhanu Chopra, Forbes, 3 Sep. 2024

Word History

Etymology

New Latin, from Latin radius ray

First Known Use

1898, in the meaning defined above

Phrases Containing radium

• radium therapy

Kids Definition

radium

noun

ra·​di·​um ˈrād-ē-əm 

: a strongly radioactive shining white metallic element that is chemically similar to barium, occurs in combination in very small quantities in minerals (as pitchblende), and is used in the treatment of cancer see element

Medical Definition

radium

noun

ra·​di·​um ˈrād-ē-əm 

often attributive

: an intensely radioactive shining white metallic element that resembles barium chemically, that occurs in combination in minute quantities in minerals (as pitchblende or carnotite) principally as the isotope of mass number 226 formed from uranium 238, having a half-life of 1620 years, and emitting alpha particles and gamma rays to form radon, and that is used chiefly in luminous materials and in the treatment of cancer

—symbol Ra see Chemical Elements Table