enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    The nitrogen atom has only 6 electrons assigned to it. One of the lone pairs on an oxygen atom must form a double bond, but either atom will work equally well. Therefore, there is a resonance structure. Tie up loose ends. Two Lewis structures must be drawn: Each structure has one of the two oxygen atoms double-bonded to the nitrogen atom.

  3. Molecular graph - Wikipedia

    en.wikipedia.org/wiki/Molecular_graph

    In some important cases (topological index calculation etc.) the following classical definition is sufficient: a molecular graph is a connected, undirected graph which admits a one-to-one correspondence with the structural formula of a chemical compound in which the vertices of the graph correspond to atoms of the molecule and edges of the ...

  4. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    The methods by which one can determine the structure of a molecule is called structural elucidation.These methods include: concerning only connectivity of the atoms: spectroscopies such as nuclear magnetic resonance (proton and carbon-13 NMR), various methods of mass spectrometry (to give overall molecular mass, as well as fragment masses).Techniques such as absorption spectroscopy and the ...

  5. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    This angle may be calculated from the dot product of the two vectors, defined as a ⋅ b = ‖ a ‖ ‖ b ‖ cos θ where ‖ a ‖ denotes the length of vector a. As shown in the diagram, the dot product here is –1 and the length of each vector is √ 3, so that cos θ = – ⁠ 1 / 3 ⁠ and the tetrahedral bond angle θ = arccos ...

  6. Structural formula - Wikipedia

    en.wikipedia.org/wiki/Structural_formula

    Skeletal structural formula of Vitamin B 12.Many organic molecules are too complicated to be specified by a molecular formula.. The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are possibly arranged in the real three-dimensional space.

  7. Chemical bonding of water - Wikipedia

    en.wikipedia.org/wiki/Chemical_bonding_of_water

    2 O) is a simple triatomic bent molecule with C 2v molecular symmetry and bond angle of 104.5° between the central oxygen atom and the hydrogen atoms. Despite being one of the simplest triatomic molecules, its chemical bonding scheme is nonetheless complex as many of its bonding properties such as bond angle, ionization energy, and electronic ...

  8. History of molecular theory - Wikipedia

    en.wikipedia.org/wiki/History_of_molecular_theory

    Lines are drawn between atoms that are bonded to one another; occasionally, pairs of dots are used instead of lines. Excess electrons that form lone pairs are represented as pair of dots, and are placed next to the atoms on which they reside: Lewis dot structures of the Nitrite-ion. To summarize his views on his new bonding model, Lewis states ...

  9. Atom - Wikipedia

    en.wikipedia.org/wiki/Atom

    This is a form of nuclear decay. Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds such as molecules or crystals. The ability of atoms to attach and detach from each other is responsible for most of the physical changes observed in nature. Chemistry is the science that studies these changes.