| Name | rubidium |
|---|---|
| Symbol | Rb |
| Atomic Weight | 85.4678 |
| Atomic Number | 37 |
| CAS ID | 7440-17-7 |
| Group Number | 1 |
| Group Name | Alkali Metal |
| Period Number | 5 |
| Origin of Name | Latin, rubidius = "deepest red." |
| Year Discovered | 1861 |
| Discovery Credits | W. Noddack, Ida Tacke, and O. Berg in Berlin, Germany. |
| Class | Metallic |
| Color | Silvery White |
| Standard State | Solid at 77 F & 298 K |
| Description | Very soft metal with silvery white luster
when cut. Ignites in air and reacts violently with water. Finds little use
outside research. Minerals with a high Rb content are use for age-dating
by the Rb-Sr isotope method. Most minerals containing potassium (K) also
contain Rb in trace amounts. Diagnostic tests: |