When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. HCN channel - Wikipedia

    en.wikipedia.org/wiki/HCN_channel

    HCN4 is the main isoform expressed in the sinoatrial node, but low levels of HCN1 and HCN2 have also been reported.The current through HCN channels, called the pacemaker current (I f), plays a key role in the generation and modulation of cardiac rhythmicity, [13] as they are responsible for the spontaneous depolarization in pacemaker action potentials in the heart.

  3. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    The number of electron pairs in the valence shell of a central atom is determined after drawing the Lewis structure of the molecule, and expanding it to show all bonding groups and lone pairs of electrons. [1]: 410–417 In VSEPR theory, a double bond or triple bond is treated as a single bonding group. [1]

  4. Chemical graph generator - Wikipedia

    en.wikipedia.org/wiki/Chemical_graph_generator

    Molecular structure generation is a branch of graph generation problems. [1] Molecular structures are graphs with chemical constraints such as valences, bond multiplicity and fragments. These generators are the core of CASE systems. In a generator, the molecular formula is the basic input.

  5. 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 connected to one another. [1]

  6. Molecular graph - Wikipedia

    en.wikipedia.org/wiki/Molecular_graph

    A chemical graph is a labeled graph whose vertices correspond to the atoms of the compound and edges correspond to chemical bonds. Its vertices are labeled with the kinds of the corresponding atoms and edges are labeled with the types of bonds. [1] For particular purposes any of the labelings may be ignored. A hydrogen-depleted molecular graph ...

  7. Molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Molecular_geometry

    In accordance with the VSEPR (valence-shell electron pair repulsion theory), the bond angles between the electron bonds are arccos(− ⁠ 1 / 3 ⁠) = 109.47°. For example, methane (CH 4) is a tetrahedral molecule. Octahedral: Octa-signifies eight, and -hedral relates to a face of a solid, so "octahedral" means "having eight faces". The bond ...

  8. Walsh diagram - Wikipedia

    en.wikipedia.org/wiki/Walsh_diagram

    Walsh diagrams in conjunction with molecular orbital theory can also be used as a tool to predict reactivity. By generating a Walsh Diagram and then determining the HOMO/LUMO of that molecule, it can be determined how the molecule is likely to react. In the following example, the Lewis acidity of AH 3 molecules such as BH 3 and CH 3 + is predicted.

  9. Graph labeling - Wikipedia

    en.wikipedia.org/wiki/Graph_labeling

    In the mathematical discipline of graph theory, a graph labeling is the assignment of labels, traditionally represented by integers, to edges and/or vertices of a graph. [1] Formally, given a graph G = (V, E), a vertex labeling is a function of V to a set of labels; a graph with such a function defined is called a vertex-labeled graph.