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Francium is the rarest naturally occurring element on Earth
Fewer than thirty grammes of francium exist in the entire terrestrial crust at any time
Francium is an extremely unstable radioactive alkali metal created briefly during the decay chain of uranium and thorium. With a half-life of only 22 minutes for its most stable isotope, francium decays away almost as fast as it forms. Scientists estimate that less than 30 grammes of natural francium exist across Earth's entire crust.
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Tags: chemistry, francium, radioactivity
Francium is the rarest naturally occurring element on Earth: the short answers
- Where does this come from, and can I check it?
- Fewer than thirty grammes of francium exist in the entire terrestrial crust at any time. The figure is taken from US Department of Energy, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
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