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  2. Ammonia borane - Wikipedia

    en.wikipedia.org/wiki/Ammonia_borane

    The molecule adopts a structure similar to that of ethane, with which it is isoelectronic. The B−N distance is 1.58(2) Å. The B−H and N−H distances are 1.15 and 0.96 Å, respectively. Its similarity to ethane is tenuous since ammonia borane is a solid and ethane is a gas: their melting points differing by 284 °C.

  3. Boron trifluoride - Wikipedia

    en.wikipedia.org/wiki/Boron_trifluoride

    BF 3 is commonly referred to as "electron deficient," a description that is reinforced by its exothermic reactivity toward Lewis bases. In the boron trihalides, BX 3, the length of the B–X bonds (1.30 Å) is shorter than would be expected for single bonds, [7] and this shortness may indicate stronger B–X π-bonding in the fluoride.

  4. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    The bond angle for a symmetric tetrahedral molecule such as CH 4 may be calculated using the dot product of two vectors. As shown in the diagram at left, the molecule can be inscribed in a cube with the tetravalent atom (e.g. carbon) at the cube centre which is the origin of coordinates, O. The four monovalent atoms (e.g. hydrogens) are at four ...

  5. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    [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.

  6. Triple point - Wikipedia

    en.wikipedia.org/wiki/Triple_point

    A typical phase diagram.The solid green line applies to most substances; the dashed green line gives the anomalous behavior of water. In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. [1]

  7. Linnett double-quartet theory - Wikipedia

    en.wikipedia.org/wiki/Linnett_Double-Quartet_Theory

    (a) The dot-and-cross diagram of the simplified LDQ structure of digermyne. The nuclei are as indicated and the electrons are denoted by either dots or crosses, depending on their relative spins. The ellipse in the centre indicates the relative disposition of the electrons around the germanium-germanium internuclear axis.

  8. Ethylene (data page) - Wikipedia

    en.wikipedia.org/wiki/Ethylene_(data_page)

    Gas properties Std enthalpy change of formation, Δ f H o gas +52.47 kJ/mol Standard molar entropy, S o gas: 219.32 J/(mol K) Enthalpy of combustion, Δ c H o –1387.4 kJ/mol Heat capacity, c p: 42.9 J/(mol K) van der Waals' constants [1] a = 453.02 L 2 kPa/mol 2 b = 0.05714 liter per mole

  9. Molecular orbital diagram - Wikipedia

    en.wikipedia.org/wiki/Molecular_orbital_diagram

    MO diagram of dihydrogen Bond breaking in MO diagram. The smallest molecule, hydrogen gas exists as dihydrogen (H-H) with a single covalent bond between two hydrogen atoms. As each hydrogen atom has a single 1s atomic orbital for its electron, the bond forms by overlap of these two atomic orbitals. In the figure the two atomic orbitals are ...