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Radium-223 dichloride (USP, radium chloride Ra 223), tradename Xofigo (formerly Alpharadin), is an alpha-emitting radiopharmaceutical. Bayer received FDA approval for this drug to treat prostate cancer osteoblastic bone metastases in May 2013. Radium-223 chloride is one of the most potent ((antineoplastic drugs)) known.
[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
This book contains predicted electron configurations for the elements up to 172, as well as 184, based on relativistic Dirac–Fock calculations by B. Fricke in Fricke, B. (1975). Dunitz, J. D. (ed.). "Superheavy elements a prediction of their chemical and physical properties". Structure and Bonding. 21. Berlin: Springer-Verlag: 89– 144.
Grayed out electron numbers indicate subshells filled to their maximum. Bracketed noble gas symbols on the left represent inner configurations that are the same in each period. Written out, these are: He, 2, helium : 1s 2 Ne, 10, neon : 1s 2 2s 2 2p 6 Ar, 18, argon : 1s 2 2s 2 2p 6 3s 2 3p 6 Kr, 36, krypton : 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 ...
A charge number also can help when drawing Lewis dot structures. For example, if the structure is an ion, the charge will be included outside of the Lewis dot structure. Since there is a negative charge on the outside of the Lewis dot structure, one electron needs to be added to the structure.
A key trait of LDQ theory that is shared with Lewis theory is the importance of using formal charges to determine the most important electronic structure. [19] LDQ theory produces the spatial distributions of the electrons by considering the two fundamental physical properties of said electrons:
Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra 3 N 2).
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols, normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.