Radium-223
| General | |
|---|---|
| Symbol | 223Ra |
| Names | radium-223, actinium X, AcX |
| Protons (Z) | 88 |
| Neutrons (N) | 135 |
| Nuclide data | |
| Half-life (t1/2) | 11.43±0.05 d |
| Isotope mass | 223.0185007(22) Da |
| Parent isotopes | 227Th 223Fr |
| Decay products | 219Rn |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| α | 5.979 |
| Isotopes of radium Complete table of nuclides | |
Radium-223 (223Ra, Ra-223) is an isotope of radium with an 11.4-day half-life. It was discovered in 1905 by T. Godlewski, a Polish chemist from Kraków, and was historically known as actinium X (AcX). Radium-223 dichloride is an alpha particle-emitting radiotherapy drug that mimics calcium and forms complexes with hydroxyapatite at areas of increased bone turnover. The principal use of radium-223, as a radiopharmaceutical to treat metastatic cancers in bone, takes advantage of its chemical similarity to calcium, and the short range of the alpha radiation it emits.