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The Avogadro constant, commonly denoted N A [1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 10 23 mol −1 (reciprocal moles). [3] [4] It is this defined number of constituent particles (usually molecules, atoms, ions, or ion pairs—in general, entities) per mole and used as a normalization factor in relating the amount of substance, n(X), in a sample of a ...
Sodium is a chemical element; it has symbol Na (from Neo-Latin natrium) and atomic number 11. It is a soft, silvery-white, highly reactive metal . Sodium is an alkali metal , being in group 1 of the periodic table.
Expressing resonance when drawing Lewis structures may be done either by drawing each of the possible resonance forms and placing double-headed arrows between them or by using dashed lines to represent the partial bonds (although the latter is a good representation of the resonance hybrid which is not, formally speaking, a Lewis structure).
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.
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). [7] In compounds, sodium is usually ionically bonded to water and anions and is ...
There are 20 isotopes of sodium (11 Na), ranging from 17 Na to 39 Na (except for the still-unknown 36 Na and 38 Na), [4] and five isomers (two for 22 Na, and one each for 24 Na, 26 Na, and 32 Na). 23 Na is the only stable (and the only primordial) isotope. It is considered a monoisotopic element and it has a standard atomic weight of 22.989 769 ...
Sodium, symbol Na, a chemical element; Avogadro constant (N A) Nucleophilic addition, a type of reaction in organic chemistry; Numerical aperture, a number that characterizes a range of angles in an optical system; nA, the symbol for nanoampere; Naturally aspirated engine
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs.