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  2. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are arccos (− ⁠ 1 / 3 ⁠ ) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane ( CH 4 ) [ 1 ] [ 2 ] as well as its heavier analogues .

  3. Geometry index - Wikipedia

    en.wikipedia.org/wiki/Geometry_index

    where: β > α are the two greatest valence angles of coordination center; θ = cos −1 (− 1 ⁄ 3) ≈ 109.5° is a tetrahedral angle. Extreme values of τ 4 and τ 4 ′ denote exactly the same geometries, however τ 4 ′ is always less or equal to τ 4 so the deviation from ideal tetrahedral

  4. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    [1]: 398 For example in the molecule methyl isocyanate (H 3 C-N=C=O), the two carbons and one nitrogen are central atoms, and the three hydrogens and one oxygen are terminal atoms. [1]: 416 The geometry of the central atoms and their non-bonding electron pairs in turn determine the geometry of the larger whole molecule.

  5. Molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Molecular_geometry

    Angular: Angular molecules (also called bent or V-shaped) have a non-linear shape. For example, water (H 2 O), which has an angle of about 105°. A water molecule has two pairs of bonded electrons and two unshared lone pairs. Tetrahedral: Tetra-signifies four, and -hedral relates to a face of a solid, so "tetrahedral" literally means "having ...

  6. Cyclohexane conformation - Wikipedia

    en.wikipedia.org/wiki/Cyclohexane_conformation

    A monosubstituted cyclohexane is one in which there is one non-hydrogen substituent in the cyclohexane ring. The most energetically favorable conformation for a monosubstituted cyclohexane is the chair conformation with the non-hydrogen substituent in the equatorial position because it prevents high steric strain from 1,3 diaxial interactions. [11]

  7. Ring strain - Wikipedia

    en.wikipedia.org/wiki/Ring_strain

    In alkanes, optimum overlap of atomic orbitals is achieved at 109.5°. The most common cyclic compounds have five or six carbons in their ring. [6] Adolf von Baeyer received a Nobel Prize in 1905 for the discovery of the Baeyer strain theory, which was an explanation of the relative stabilities of cyclic molecules in 1885.

  8. Crystal structure - Wikipedia

    en.wikipedia.org/wiki/Crystal_structure

    One good example of this is the quartz form of silicon dioxide, or SiO 2. In the vast majority of silicates, the Si atom shows tetrahedral coordination by 4 oxygens. All but one of the crystalline forms involve tetrahedral {SiO 4} units linked together by shared vertices in different arrangements. In different minerals the tetrahedra show ...

  9. Trigonal pyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Trigonal_pyramidal...

    The electron pair arrangement of ammonia is tetrahedral: the two lone electrons are shown in yellow, the hydrogen atoms in white The molecular geometry can be inferred from the electron pair arrangement, showing that ammonia has trigonal pyramidal geometry.