2.2.2 - Bonding and Structure

• What is average bond enthalpy?

  The average energy required to break a bond
• How is average bond enthalpy used in chemistry?

  As a measurement of the strength of a covalent bond
• How is average bond enthalpy measured?

  Using a variety of molecules with specific bonds
• What is a bonding pair?

  A pair of outer-shell electrons involved in bonding
• Why are bonding pairs important in chemistry?

  They are involved in the formation of covalent bonds
• How do bonding pairs relate to covalent bonds?

  Bonding pairs are essential for covalent bond formation
• What is a covalent bond?

  A strong bond between 2 atoms
• How is a dative covalent bond different from a regular covalent bond?

  Both electrons in a shared pair come from one atom
• What does electronegativity measure?

  The ability to attract bonding electrons
• How does electronegativity change in the periodic table?

  It increases towards fluorine (F)
• What does the Electron Pair Repulsion Theory state?

  Electron pairs repel and position as far apart
• Why do lone pairs offer more repulsion than bonding pairs?

  They are closer to the nucleus of the central atom
• What is hydrogen bonding?

  Bonding between molecules with N, O, or F and H
• What allows the formation of a hydrogen bond?

  A lone pair on the electronegative atom
• What are intermolecular forces?

  Interactions between different molecules
• What are the types of intermolecular forces?

  Permanent dipole-dipole and induced dipole-dipole
• What is an ionic bond?

  Electrostatic attraction between positive and negative ions
• What are ionic compounds made of?

  Oppositely charged ions
• What are the typical properties of ionic compounds?

  High melting and boiling points, soluble
• When can ionic compounds conduct electricity?

  When liquid or aqueous, not solid
• What is an ionic lattice?

  A giant structure of oppositely charged ions
• What is the shape of a linear molecule?

  Central atom has 2 bonding pairs
• What are London (Dispersion) Forces?

  Induced dipole-dipole interactions from electron movement
• What is a lone pair?

  A pair of outer-shell electrons not bonding
• What are macroscopic properties?

  Properties of bulk material, not individual atoms
• What is the shape of a non-linear molecule?

  Central atom has 2 bonding pairs and 2 lone pairs
• What is the shape of an octahedral molecule?

  Central atom has 6 bonding pairs
• What is a permanent dipole?

  A permanent uneven distribution of charge
• What defines a polar bond?

  A covalent bond with a permanent dipole
• What causes a molecule to be polar?

  Polar bonds with dipoles that don't cancel
• What is the shape of a pyramidal molecule?

  Central atom with 3 bonding pairs and 1 lone pair
• What is a simple molecular lattice?

  • Solid structure of covalently bonded molecules
  • Attracted by intermolecular forces
  • Examples: Iodine (I), ice
  • Low melting and boiling points
  • Insoluble in water, soluble in organic solvents
  • Do not conduct electricity
• What is the shape of a tetrahedral molecule?

  Central atom with 4 bonding pairs
• What is the shape of a trigonal bipyramidal molecule?

  Central atom with 5 bonding pairs
• What is the shape of a trigonal planar molecule?

  Central atom with 3 bonding pairs