Francium is a chemical element; it has symbol Fr and atomic number 87. It is extremely radioactive; its most stable isotope, francium-223 (originally called actinium K after the natural …

francium (Fr), heaviest chemical element of Group 1 (Ia) in the periodic table, the alkali metal group. It exists only in short-lived radioactive forms. Natural francium cannot be isolated in …

Jul 26, 2022 · Francium — the 87th element on the periodic table — is a naturally occurring, but incredibly rare, radioactive element. It forms and decays extremely quickly, so it has no …

Francium, number 87, was the last of these elements to be discovered in nature. From its position in the table, it was clear that element 87 would be a reactive alkali metal, the heaviest member …

Francium definition, discovery, properties (atomic mass, color, melting point, atomic number, electron configuration), reactivity in water, common uses

Jun 9, 2025 · Francium is a rare and highly unstable element with the atomic number 87 and symbol Fr. Discovered in 1939, francium decays quickly, making it the second rarest natural …

Francium is a heavy, unstable, radioactive metal with a maximum half-life of only 22 minutes. It has a low melting point (27 o C, 81 o F) and, if enough of it could be accumulated, it would be …

Francium, the heaviest known member of the alkali metals series, occurs as a result of an alpha disintegration of actinium. It can also be made artificially by bombarding thorium with protons. …

Francium may be the rarest element found on the Earth's surface. Some experts believe that no more than 15 grams (less than an ounce) of the element exists in the Earth's crust. The …

Jan 13, 2007 · Francium is the heaviest of the naturally occuring alkali elements -- the left most column of the periodic table of the elements. It has a 87 protons and between 120 to 140 …