Chemistry Ch. 9 Vocab

  1. covalent bond
    the chemical bond that results from the sharing of valence electrons
  2. molecule
    formed when two or more atoms bond covalently
  3. Lewis structures
    use electron-dot diagrams to show how electrons are arranged in molecules (H-H)
  4. sigma bond
    single covalent bond; occurs when the electron pair is shared in an area centered between the two atoms
  5. pi bond
    multiple covalent bond; formed when parallel orbitals overlap to share electrons
  6. bond length
    the distance between the two bonding nuclei at the position of maximum attraction; determined by the size of the atoms and how many electron pairs are shared--as the number of shared electron pairs increases, bond length decreases
  7. bond dissociation energy
    the amount of energy required to break a specific covalent bond
  8. endothermic reaction
    occurs when a greater amount of energy is required to break the existing bonds in the reactants than is released when the new bonds form in the product molecules (cold)
  9. exothermic reaction
    occurs when more energy is released forming new bonds than is required to break bonds in the initial reactants (hot)
  10. binary acid
    contains hydrogen and one other element
  11. oxyanion
    a polyatomic ion that contains oxygen
  12. oxyacid
    any acid that contains hydrogen and an oxyanion
  13. structural formula
    a molecular model that uses letter symbols and bonds to show relative positions of atoms
  14. resonance
    a condition that occurs when more than one valid Lewis structure can be written for a molecule and ion
  15. resonance structures
    the two or more correct Lewis structures that represent a single molecule or ion
  16. coordinate covalent bond
    forms when one atom donates a pair of electrons to be shared with an atom or ion that needs two electrons to become stable
  17. expanded octet
    compounds that have central atoms that contain more than eight valence electrons; occurs with elements in period three or higher
  18. VSEPR model
    Valence Shell Electron Pair Repulsion model; based on an arrangement that minimizes the repulsion of shared and unshared pairs of electrons around the central atom; used to determine molecular shape
  19. bond angle
    the angle formed by any two terminal atoms and the central atom
  20. hybridization
    a process in which atomic orbitals are mixed to form new, identical hybrid orbitals; each hybrid orbital contains one electron that it can share with another atom; carbon does this the most
  21. electron affinity
    a measure of the tendency of an atom to accept an electron; increases as the atomic number increases within a period and decreases as the atomic number increases within a group
  22. polar covalent
    results from unequal sharing because of a difference in electronegativity
  23. van der Waals forces/intermolecular forces
    weak forces of attraction between individual molecules; weaker than the bonds that join atoms in a molecule or ions in an ionic compound
Card Set
Chemistry Ch. 9 Vocab
Vocabulary words from Glencoe Chemistry chapter 9, Covalent Bonding