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.

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...

Francium is the shiny metal in its pure state and exist in liquid form at room temperature rather than a solid. Francium belongs to alkali group of the periodic table so its physical properties are similar with alkali group elements.

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.

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

2019年11月4日 · 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 element after astatine. Due to its rarity and instability, francium is mainly used for research, including spectroscopic experiments.

2024年10月15日 · As it happens, the metal’s only naturally-occurring isotope - francium-223 - forms during the radioactive decay of actinium.

2018年3月2日 · Francium (pronounced as FRAN-see-em) is an alkali metal denoted by the symbol, Fr. No more than 15 grams of the element is found in the earth’s crust [1, 5]. Its most stable isotope is Francium-223 having a half-life of 22 minutes that either undergo beta decay or alpha decay to form radium-223 and astatine-219, respectively [3].

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.