Discovery
Rubidium was almost discovered in the 1760s, when a Lithium Potassium mineral named Lepidolite was observed behaving oddly. When thrown on coals, it frothed and then hardened like glass. Analysis showed it contained Lithium and Potassium but what they didn't know at the time was that it also contained Rubidium. In 1861, Robert Bunsen and Gustav Kirchhoff dissolved the ore in acid and then precipitated the result, which also contained an unknown heavier alkali metal. Rubidium itself was eventually produced in 1928. The name comes from the two ruby-red lines produced when the element is analysed in the atomic spectrum.
Characteristics
| Group | Period | Block | Number | Configuration |
|---|---|---|---|---|
| 1 | 5 | s | 37 | [Kr] 5s1 |
| Melting Point | Boiling Point | Density | Mass | Key Isotope |
| 39.30°C | 688°C | 1.53 g cm | 85.468 | 85Rb, 87Rb |
Rubidium is a soft, silvery-white metal, but unlike the previous alkali metals it will ignite in air. It burns with a violet flame.
It's unknown how much rubidium is on the planet at any one time because it occurs in such low quantities.
| Atomic Radius | Electron Affinity | Covalent Radius | Electronegativity |
|---|---|---|---|
| 3.03 | 46.884 | 2.15 | 0.82 |
Uses
Rubidium is rarely used outside of research. It's been used in photocells that convert light into electricity and to remove traces of Oxygen from vacuum tubes, but outside of that it serves little use.
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