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[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.
Sodium atoms have 11 electrons, one more than the stable configuration of the noble gas neon. As a result, sodium usually forms ionic compounds involving the Na + cation. [1] Sodium is a reactive alkali metal and is much more stable in ionic compounds. It can also form intermetallic compounds and organosodium compounds.
Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na +) and iodide anions (I −) in a crystal lattice. It is used mainly as a nutritional supplement and in organic chemistry.
The most important sodium compounds are table salt (NaCl), soda ash (Na 2 CO 3), baking soda (NaHCO 3), caustic soda (NaOH), sodium nitrate (NaNO 3), di- and tri-sodium phosphates, sodium thiosulfate (Na 2 S 2 O 3 ·5H 2 O), and borax (Na 2 B 4 O 7 ·10H 2 O). [24] In compounds, sodium is usually ionically bonded to water and anions and is ...
The circumstances under which a compound will have ionic or covalent character can typically be understood using Fajans' rules, which use only charges and the sizes of each ion. According to these rules, compounds with the most ionic character will have large positive ions with a low charge, bonded to a small negative ion with a high charge. [25]
Sodium peroxide is an inorganic compound with the formula Na 2 O 2.This yellowish solid is the product of sodium ignited in excess oxygen. [3] It is a strong base. This metal peroxide exists in several hydrates and peroxyhydrates including Na 2 O 2 ·2H 2 O 2 ·4H 2 O, Na 2 O 2 ·2H 2 O, Na 2 O 2 ·2H 2 O 2, and Na 2 O 2 ·8H 2 O. [4] The octahydrate, which is simple to prepare, is white, in ...
Other rules exist for other elements, such as the duplet rule for hydrogen and helium, and the 18-electron rule for transition metals. The valence electrons can be counted using a Lewis electron dot diagram as shown at the right for carbon dioxide. The electrons shared by the two atoms in a covalent bond are counted twice, once for each atom ...
This electrochemical theory of valence found its most elaborate expression in the work of Richard Abegg in 1904, [39] but Lewis’ version of this theory was the only one to be embodied in a concrete atomic model. Again Lewis’ theory did not interest his Harvard mentors, who, like most American chemists of that time, had no taste for such ...