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  2. Pi bond - Wikipedia

    en.wikipedia.org/wiki/Pi_bond

    A typical triple bond, for example in acetylene (HC≡CH), consists of one sigma bond and two pi bonds in two mutually perpendicular planes containing the bond axis. Two pi bonds are the maximum that can exist between a given pair of atoms. Quadruple bonds are extremely rare and can be formed only between transition metal atoms, and consist of ...

  3. Tennessine - Wikipedia

    en.wikipedia.org/wiki/Tennessine

    Tennessine is a synthetic chemical element; it has symbol Ts and atomic number 117. It has the second-highest atomic number and joint-highest atomic mass of all known elements and is the penultimate element of the 7th period of the periodic table.

  4. Ball-and-stick model - Wikipedia

    en.wikipedia.org/wiki/Ball-and-stick_model

    Double and triple bonds are usually represented by two or three curved rods, respectively, or alternately by correctly positioned sticks for the sigma and pi bonds. In a good model, the angles between the rods should be the same as the angles between the bonds , and the distances between the centers of the spheres should be proportional to the ...

  5. Chemical bond - Wikipedia

    en.wikipedia.org/wiki/Chemical_bond

    See sigma bonds and pi bonds for LCAO descriptions of such bonding. [22] Molecules that are formed primarily from non-polar covalent bonds are often immiscible in water or other polar solvents, but much more soluble in non-polar solvents such as hexane. A polar covalent bond is a covalent bond with a significant ionic character. This means that ...

  6. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    Periodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals. The f-block actually fits between groups 2 and 3 ; it is usually shown at the foot of the table to save horizontal space.

  7. Graphene - Wikipedia

    en.wikipedia.org/wiki/Graphene

    Sigma and pi bonds in graphene. Sigma bonds result from an overlap of sp 2 hybrid orbitals, whereas pi bonds emerge from tunneling between the protruding p z orbitals. Three of the four outer- shell electrons of each atom in a graphene sheet occupy three sp 2 hybrid orbitals – a combination of orbitals s, p x and p y — that are shared with ...

  8. Phosphorus triiodide - Wikipedia

    en.wikipedia.org/wiki/Phosphorus_triiodide

    Phosphorus triiodide (PI 3) is an inorganic compound with the formula PI 3. A red solid, it is too unstable to be stored for long periods of time; it is, nevertheless, commercially available. [ 2 ] It is widely used in organic chemistry for converting alcohols to alkyl iodides and also serves as a powerful reducing agent.

  9. Pauling's principle of electroneutrality - Wikipedia

    en.wikipedia.org/wiki/Pauling's_principle_of...

    Pauling invoked the principle of electroneutrality in a 1952 paper to suggest that pi bonding is present, for example, in molecules with 4 Si-O bonds. [8] The oxygen atoms in such molecules would form polar covalent bonds with the silicon atom because their electronegativity (electron withdrawing power) was higher than that of silicon.