GPS satellites above your head pinpoint coordinates to within a meter. This is possible thanks to rubidium-87 atomic clocks inside each satellite. They drift by only one second in 300 years — accurate enough for navigation to work.
Rubidium is one of the most reactive metals. It ignites in air and explodes on contact with water — even more vigorously than potassium. And its melting point is just 39.3°C: on a hot day, a chunk of rubidium would melt in your palm.
In 2001, the Nobel Prize in Physics was awarded for creating a Bose-Einstein condensate from rubidium-87 atoms. When cooled to nanokelvins, rubidium atoms enter a single quantum state — behaving as one giant wave.
Rubidium isn't rare in nature (78 ppm — more than zinc) but is dispersed. It's extracted from lepidolite and pollucite minerals. Annual production is only 2–4 tons, so the price is high: ~$15,000 per kilogram.
Rubidium is extremely reactive: it spontaneously ignites in air and explodes on contact with even a trace of water. Causes severe chemical burns to skin and eyes. Stored in sealed ampoules under argon or in mineral oil. Work only in an inert atmosphere with full body and eye protection.
Rubidium was named from Latin 'rubidus' (dark red) — for its bright red-violet spectral lines. Discovered by Bunsen and Kirchhoff in 1861.
Rubidium is so reactive it spontaneously ignites in air and explodes on contact with water — even more vigorously than potassium.
Melting point is just 39.3°C. On a hot day, a chunk of rubidium would melt in your palm (if it didn't ignite first).
The 2001 Nobel Prize in Physics — for a Bose-Einstein condensate of rubidium-87 atoms at billionths of a degree above absolute zero.
Rubidium-87 atomic clocks in GPS satellites drift by one second in 300 years. Without them, navigation wouldn't work.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
85Rb | 84.911790 | 72.17% | stable | — |
87Rb☢ | 86.909181 | 27.83% | 4.9×10¹⁰ years | β− |
Spectroscopic analysis of lepidolite