Ra
Radium Symbol (Ra)
Radium is element 88 of the periodic table. Copy its symbol Ra and see its atomic weight, electron configuration and physical properties.
What does Ra mean?
Ra is the chemical symbol for radium, element number 88 in the periodic table. Radium is an alkaline earth metal in group 2, period 7. It is a solid at room temperature and was discovered in 1898.
Codes and properties
| Chemical symbol | Ra |
|---|---|
| Atomic number (Z) | 88 |
| Mass number (no standard atomic weight) | [226] |
| Group / period | 2 / 7 |
| Element category | alkaline earth metal |
| Electron configuration | [Rn]7s² |
| State at 20 °C | Solid |
| Oxidation states | +2 |
| Electronegativity (Pauling) | 0.9 |
| Melting point | 973 K (699.85 °C) |
| Boiling point | 1413 K (1139.85 °C) |
| Density | 5 g/cm³ |
| Discovered | 1898 |
How to type Ra
- Plain text: type
Ra— element symbols are ordinary Latin letters, with the first letter capitalised and the second lowercase. - Subscripts in formulas: use Unicode subscript digits (₀₁₂₃₄₅₆₇₈₉) for formulas such as H₂O — copy them from the chemistry keyboard.
- LaTeX: write
\mathrm{Ra}in math mode, or use the mhchem package:\ce{Ra}. - HTML:
Ra; for subscripts use<sub>, e.g.H<sub>2</sub>O.
Frequently asked questions
What is the chemical symbol for radium?
The chemical symbol for radium is Ra.
What is the atomic number of radium?
Radium has atomic number 88, meaning each atom has 88 protons.
What is the electron configuration of radium?
The ground-state electron configuration of radium is [Rn]7s².
Related symbols
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Reference: Radium on PubChem (NIH)