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 decay chain in which it appears), has a half-life of only 22 minutes.

Element Francium (Fr), Group 1, Atomic Number 87, s-block, Mass [223]. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images.

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 visible, weighable amounts, for only 24.5 grams (0.86 ounce) occur at …

2022年7月26日 · 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 practical uses, and it...

2019年11月4日 · Francium is a highly radioactive alkali metal with the atomic number 87 and element symbol Fr. Although it occurs naturally, it decays so quickly it's very rare. In fact, scientists have never had a large enough sample of francium to know what it actually looks like!

2018年3月2日 · Francium definition, discovery, properties (atomic mass, color, melting point, atomic number, electron configuration), reactivity in water, common uses

Francium is a chemical element with symbol Fr and atomic number 87. Classified as a n alkali metal, Francium is a solid at room temperature. B. Cordero, V. Gómez, A.E. Platero-Prats, M. Revés, J. Echeverría, E. Cremades, F. Barragán, S. Alvarez, Dalton Trans. 2008, 21, 2832-2838. DOI:10.1039/b801115j PMID:18478144.

Francium is a chemical element with the chemical symbol Fr and an atomic number of 87. It is a metal. In chemistry it is placed in a group of metal elements named the alkali metals. Francium is very radioactive. It is in very small amounts in uranium and thorium ores.

2023年10月9日 · Francium is a chemical element with the atomic number 87 and it is represented by the symbol ‘Fr’ in the periodic table. It belongs to Group 1 and Period 7 of the periodic chart. It is classified as an alkali metal. It is a soft, low-melting, silvery-white metal.

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. While it occurs naturally in uranium minerals, there is probably less than an ounce of francium at any time in the total crust of the earth.