rubídium

Rubidium is a chemical element with the symbol Rb and atomic number 37. It is an alkali metal, meaning it is in the first group of the periodic table. Rubidium is a soft, silvery-white metal that is highly reactive. It is never found in its elemental form in nature, as it readily oxidizes in air and reacts violently with water.

Rubidium is relatively abundant in the Earth's crust, found in minerals like lepidolite and pollucite. It is typically extracted from these minerals through chemical processes. Rubidium has several isotopes, with rubidium-87 being the most common and radioactive. This radioactivity is utilized in rubidium-87 dating, a method used to determine the age of rocks and minerals.

In its pure form, rubidium is used in the production of vacuum tubes and as a component in certain types of glass. Rubidium salts have found applications in medicine, particularly in treatments for depression and neurological disorders, though these uses are still under investigation. Due to its low ionization energy, rubidium is also explored for use in ion propulsion systems for spacecraft. The characteristic red spectral lines of rubidium are also used in atomic clocks, contributing to highly accurate timekeeping.