Quick Facts
| Property | Value |
|---|---|
| Symbol | Ra |
| Atomic Number | 88 |
| Atomic Mass | [226] u |
| Category | Alkaline Earth Metal |
| Period | 7 |
| Group | 2 |
| Block | s |
| Electron Configuration | [Rn] 7s² |
History and Discovery
Discovered by: Marie and Pierre Curie Year of Discovery: 1898 Location: Paris, France
Etymology
From Latin "radius" meaning "ray," due to its intense radioactivity.
Applications and Uses
- Historically: luminous watch dials (caused "radium jaw" in workers)
- Cancer treatment (brachytherapy)
- Radon production for research
- Industrial radiography
Historical Tragedy
"Radium Girls" who painted watch dials developed fatal radiation poisoning in the 1920s, leading to workplace safety reforms.
Interesting Facts
- Marie Curie carried radium in her pocket and died of radiation exposure
- One gram of radium produces 1 curie of radioactivity
- Glows pale blue due to excitation of surrounding air
- "Radium water" was sold as medicine in the early 1900s
- The Radium Girls' story led to workers' rights legislation