Rubidium

Rubidium is a soft, silvery alkali metal with atomic number 37. Its easily excited atoms make it useful in atomic clocks and scientific research.

Rubidium-87: A naturally occurring radioactive isotope of rubidium with a half-life of about 49 billion years. Its atomic transition provides the frequency standard in many rubidium atomic clocks.
Global Positioning System: A satellite-based navigation system that determines position and time using signals from orbiting satellites. Rubidium clocks provide compact time references in some GPS satellites.
Periodic table: A tabular arrangement of chemical elements ordered by atomic number and grouped by recurring properties. Rubidium’s position in Group 1 predicts its broad chemical behavior.
Robert Bunsen: A German chemist who developed laboratory methods and instruments for chemical analysis, including flame spectroscopy. Bunsen and Kirchhoff used spectroscopy to identify rubidium in mineral samples.
Cesium: A soft, highly reactive alkali metal with atomic number 55. Cesium is rubidium’s heavier neighbor and is also used in atomic clocks.
Rubidium atomic clock: A frequency standard that uses a microwave transition in rubidium atoms to keep time. It turns rubidium’s stable atomic transition into a practical timekeeping signal.
Laser cooling: A technique that uses laser light to slow atoms and reduce their temperature. Rubidium atoms are commonly cooled and trapped for precision experiments.
Atomic number: The number of protons in an atom’s nucleus, which defines the chemical element. Rubidium’s 37 protons distinguish it from every other element.
Gustav Kirchhoff: A German physicist whose work in spectroscopy and electrical circuit theory shaped nineteenth-century science. Kirchhoff’s spectral analysis helped establish rubidium as a newly identified element.
Potassium: A soft, reactive alkali metal with atomic number 19 that is essential to living organisms. Potassium is a lighter Group 1 element with similar chemistry but much greater biological importance.

Linked from 10 pages