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5: Chemical Bonding - Electron Pairs and Octets

  • Page ID
    206818
  • Theories of chemical bonding invariably involve electrons. When one atom approaches another, the valence electrons, found in the outermost regions of the atoms, interact long before the nuclei can come close together. Electrons are the least massive components of an atom, and so they can relocate to produce electrostatic forces which hold atoms together. According to Coulomb’s law, such electrostatic or Coulombic forces are quite large when charges are separated by distances of a few hundred picometers—the size of an atom. Coulombic forces, then, are quite capable of explaining the strengths of the bonds by which atoms are held together.

    • 5.1: Prelude to Chemical Bonding
      Theories of chemical bonding invariably involve electrons. When one atom approaches another, the valence electrons, found in the outermost regions of the atoms, interact long before the nuclei can come close together. Electrons are the least massive components of an atom, and so they can relocate to produce electrostatic forces which hold atoms together.
    • 5.2: Ionic Bonding
      Ionic bonding involves transfer of an electron from one atom (which becomes a positively charged cation) to another (which becomes a negatively charged anion). The two ions attract strongly to form a crystal lattice.
    • 5.3: Binary Ionic Compounds and Their Properties
      All ionic compounds have numerous properties in common. Consequently, the ability to recognize an ionic compound from its formula will allow you to predict many of its properties. This is often possible in the case of a binary compound (one which contains only two elements), because formation of a binary ionic compound places quite severe restrictions on the elements involved.
    • 5.4: The Covalent Bond
      Formation of an ionic bond by complete transfer of an electron from one atom to another is possible only for a fairly restricted set of elements. Covalent bonding, in which neither atom loses complete control over its valence electrons, is much more common. In a covalent bond the electrons occupy a region of space between the two nuclei and are said to be shared by them.
    • 5.5: Polyatomic Ions
      Polyatomic ions, common in any lab, contain several atoms covalently bonded together. Often, these ions are charged and combine with metals to form ionic bonds.
    • 5.6: Ionic Compounds Containing Polyatomic Ions
      Polyatomic ions are everywhere and this pages introduces you to familiar polyatomic ions that often form ionic bonds.

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