ife will ever be discovered or synthesized. [26] Francium-223 is the fifth product of the actinium decay series as the daughter isotope of actinium-227. [17] Francium-223 then decays into radium-223 by beta decay (1149 keV decay energy), with a minor (0.006%) alpha decay path to astatine-219 (5.4 MeV decay energy). [34]
Francium-221 has a half-life of 4.8 minutes. [3] It is the ninth product of the neptunium decay series as a daughter isotope of actinium-225. [17] Francium-221 then decays into astatine-217 by alpha decay (6.457 MeV decay energy). [3]
The least stable ground state isotope is francium-215, with a half-life of 0.12 Ојs. (9.54 MeV alpha decay to astatine-211): [3] Its metastable isomer, francium-215m, is less stable still, with a half-life of only 3.5 ns. [35]
7 . Conclusion
As an individual representative of the periodic table of chemical elements Dmitry Ivanovich Mendeleyev, the element has unique chemical and physical properties
Element is of great economic importance and plays a major role in world culture
8 . References
1. Actually the least unstable isotope, Fr-223
2. Some synthetic elements, like technetium, have later been found in nature.
3. a b c defghijkl CRC Handbook of Chemistry and Physics, 4, CRC, 2006, p. 12, ISBN 0-8493-0474-1
4. a b c d e f g Price, Andy (2004-12-20). "Francium". 5. Winter, Mark. "Electron Configuration". Francium. The University of Sheffield. 6. Kozhitov, L. V.; Kol'tsov, V. B.; Kol'tsov, A. V. (2003). "Evaluation of the Surface Tension of Liquid Francium ". Inorganic Materials 39 (11): 1138-1141. doi: 10.1023/A: 1027389223381.
7. Pauling, Linus (1960). The Nature of the Chemical Bond (3rd Edn.). Cornell University Press. pp. 93. p> 8. Allred, A. L. (1961). "Electronegativity values ​​from thermochemical data". J. Inorg. Nucl. Chem. 17 (3-4): 215-221. doi: 10.1016/0022-1902 (61) 80142-5.
9. Andreev, S.V.; Letokhov, V.S.; Mishin, V.I., (1987). "Laser resonance photoionization spectroscopy of Rydberg levels in Fr ". Physical Review Letters 59: 1274-76. doi: 10.1103/PhysRevLett.59.1274.
10. Hyde, E. K. (1952). "Radiochemical Methods for the Isolation of Element 87 (Francium) ". J. Am. Chem. Soc. 74 (16): 4181-4184. doi: 10.1021/ja01136a066.
11. E. N K. Hyde Radiochemistry of Francium, Subcommittee on Radiochemistry, National Academy of Sciences-National Research Council; available from the Office of Technical Services, Dept. of Commerce, 1960.
12. Maddock, A. G. (1951). "Radioactivity of the heavy elements". Q. Rev., Chem. Soc. 3: 270-314. doi: 10.1039/QR9510500270.
13. Winter, Mark. "Uses". Francium. The University of Sheffield. 14. Bentor, Yinon. "Chemical Element.com - Francium". 15. a b c d e f Emsley, John (2001). Nature's Building Blocks. Oxford: Oxford University Press. pp. 151-153. ISBN 0-19-850341-5. p> 16. Gagnon, Steve. "Francium". Jefferson Science Associates, LLC. 17. a b c Considine, Glenn D., ed (2005). Chemical Elements, in Van Nostrand's Encyclopedia of Chemistry. New York: Wiley-Interscience. p. 332. ISBN 0-471-61525-0. p> 18. Haverlock, TJ (2003). "Selectivity of calix [4] arene-bis (benzocrown-6) in the complexation and transport of francium ion ". J Am Chem Soc 125: 1126-7. doi: 10.1021/ja0255251. PMID 12553788. p> 19. Gomez, E; Orozco, L A, and Sprouse, G D (2005-11-07). "Spectroscopy with trapped francium: advances and perspectives for weak interaction studies ". Rep. Prog. Phys. 69 (1): 79-118. doi: 10.1088/0034-4885/69/1/R02.
20. Peterson, I (1996-05-11). "Creating, cooling, trapping francium atoms". Science News 149 (19): 294. 21. a b c d e Adloff, Jean-Pierre; Kaufman, George B. (2005-09-25). Francium (Atomic Number 87), the Last Discovered Natural Element. The Chemical Educator 10 (5). Retrieved on 2007-03-26. p> 22. a b c d e Fontani, Marco (2005-09-10). "The Twilight of the Naturally-Occurring Elements: Moldavium (Ml), Sequanium (Sq) and Dor (Do) ". International Conference on the History of Chemistry. Lisbon. pp. 1-8. Archived from the original on 2006-02-24.
23. a b c d Van der Krogt, Peter (2006-01-10). "Francium". Elementymology & Elements Multidict. 24. "Alabamine & Virginium ". TIME. 1932-02-15.
