An extremely rare, highly radioactive metallic chemical element with the symbol Fr and atomic number 87, the most unstable of the first 103 elements.
Named after France by French chemist Marguerite Perey, who discovered the element in 1939 at the Curie Institute in Paris. Perey initially called it 'actinium-K' but later chose 'francium' to honor her country. The name follows the pattern of other elements named after countries, using the Latin root with the standard '-ium' suffix.
Francium is so incredibly rare and unstable that scientists estimate there are never more than 30 grams of it in the entire Earth's crust at any moment - it decays so quickly that studying it is like trying to examine a ghost! Marguerite Perey was the last person to discover a naturally occurring element, making francium the final addition to nature's periodic table.
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