Rubidium (Rb) — Element 37: Properties & Data | Aladdin Scientific
Rubidium(Rb) — Element 37
Rubidium (Rb) is a alkali metal with atomic number 37 and atomic mass 85.468. It has melting point 312.46 K (39 °C), boiling point 961 K (688 °C), density 1.53 g/cm³. It sits in group 1 and period 5 of the periodic table and was discovered in 1861.
Key facts
| Atomic mass | 85.4680 u |
|---|---|
| Electron configuration | [Kr]5s1 |
| Oxidation states | +1 |
| Electronegativity (Pauling) | 0.82 |
| Atomic radius (van der Waals) | 303 pm |
| Ionization energy | 4.177 eV |
| Electron affinity | 0.468 eV |
| Melting point | 312.46 K |
| Boiling point | 961 K |
| Density | 1.53 g/cm³ |
| Standard state | Solid |
| Year discovered | 1861 |
Frequently asked questions
What is the electron configuration of rubidium?
The ground-state electron configuration of rubidium is [Kr]5s1.
What group and period is rubidium in?
Rubidium (Rb) is in group 1 and period 5 of the periodic table, classified as a alkali metal.
What is the melting point of rubidium?
Rubidium melts at 312.46 K (39 °C).
What is the standard state of rubidium?
Rubidium is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .