37Rb

Rubidium

Alkali metalsolidblock s

Found by spectroscope in 1861, it now keeps time in atomic clocks and formed the first Bose-Einstein condensate.

Atomic number	37
Standard atomic weight	85.468 g/mol ± 0.001
Group · period	1 · 5
Electron configuration	[Kr] 5s¹

About Rubidium

Bunsen and Kirchhoff had just invented the spectroscope and used it to find caesium in 1860; rubidium followed in 1861, named for the two deep red lines in its spectrum. It is a soft alkali metal that melts at 39 °C and ignites in air, but its modern importance is atomic rather than chemical. Rubidium vapour cells make small, cheap, extremely stable frequency standards — the rubidium clock is the workhorse timekeeper in GPS satellites, cellular base stations and telecom networks, where a caesium fountain would be overkill. In 1995 Eric Cornell and Carl Wieman cooled about two thousand rubidium-87 atoms to 170 nanokelvin and produced the first Bose-Einstein condensate, a state of matter Einstein had predicted in 1925; they shared the 2001 Nobel Prize with Wolfgang Ketterle.

Use 85.468 g/mol in these solvers

Moles from Mass (n = m/M)

n = \frac{m}{M}

Opens with M = 85.468 g/mol already filled in

Gas Density from Molar Mass

\rho = \frac{PM}{RT}

Opens with M = 85.468 g/mol already filled in

Faraday's Law of Electrolysis (m = QM/nF)

m = \frac{Q M}{n F}

Opens with M = 85.468 g/mol already filled in

Ion Concentration as CaCO₃ Equivalent

C_{\mathrm{CaCO_3}} = C_{\mathrm{ion}} \times \frac{50.04}{\mathrm{EW}}

Opens with EW = 85.468 g/mol already filled in

Acid Feed to Reduce Alkalinity

\dot m = \frac{\Delta \mathrm{Alk} \, Q \times \frac{\mathrm{EW}}{50.04}}{p/100\%}

Opens with EW = 85.468 g/mol already filled in

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