Definition of radium
: an intensely radioactive brilliant white metallic element that resembles barium chemically, 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 luminous materials and in the treatment of cancer — see element table
Recent Examples of radium from the Web
Other harmful colors include fluorescent radium green, arsenic green, and uranium orange.
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Origin and Etymology of radium
New Latin, from Latin radius ray
First Known Use: 1899See Words from the same year
RADIUM Defined for English Language Learners
Definition of radium for English Language Learners
: a radioactive element that is used medically in cancer treatments
RADIUM Defined for Kids
Definition of radium for Students
: a strongly radioactive element found in very small quantities in various minerals (as pitchblende) and used in the treatment of cancer
Medical Definition of radium
: 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 element table
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