Rubidium (Rb)
"The Timekeeper, a hero who measures time with atomic precision."
A memorable persona to anchor Rb in your mind.
1.532
Grams per cm³
39.3
Celsius (°C)
303
Radius (pm)
Daily Life Link
Rubidium is found in the purple color in some fireworks.
Discovery & History
Year Discovered
1861
Discovered By
Robert Bunsen & Gustav Kirchhoff
Origin of Name
"The name is derived form the Latin ''rubidius'', meaning deepest red."
Technical Properties
Atomic Mass
85.468 u
Standard State
solid
Boiling Point
688°C
Electron Configuration
[Kr] 5s1
1st Ionization Energy
4.177 eV
Electron Affinity
N/A
Oxidation States
"Rubidium is a soft, silvery-white, highly reactive metal."
Did You Know?
It was discovered using spectroscopy by Robert Bunsen and Gustav Kirchhoff, who noticed a unique set of deep red lines in the spectrum of a mineral sample. The name comes from the Latin 'rubidus' for 'deepest red'.
Rubidium is used in some of the world's most accurate atomic clocks.
It is so reactive that it can ignite spontaneously in air and reacts violently with water.
It melts at a very low temperature of 39.3 °C (102.7 °F), meaning it would be a liquid on a very hot summer day.