| A | B |
|---|
| intermolecular bonds | forces of attraction among molecules |
| electronegativity | attraction that an atom has for electrons in a bond |
| high electronegativities | upper right of the periodic table |
| low electronegativities | lower left of the periodic table |
| dipole-dipole attractions | attractions among all polar molecules |
| polar molecule | molecule that has two different ends or poles |
| hydrogen bonding | very strong dipole-dipole attractions in very small, polar molecules |
| Nonpolar molecules exhibit what forces? | dispersion forces |
| VSEPR | electron pairs in molecules repel and stay as far apart as possible... giving a particular shapes to molecules |
| polar molecules | nonsymmetrical molecule, all bent and trigonal pyramidal molecules are polar |
| nonpolar molecules | symmetrical molecule; tetrahedral, trigonal planar, and linear (if all outside atoms are the same) |
| weak intermolecular forces | small nonpolar molecules, often gases at room temperature |
| larger dispersion forces | large nonpolar molecules that are often liquids or solids at room temperature |
| water, ammonia, hydrogen fluoride | example of hydrogen bonding |
| fluorine, carbon dioxide | example of weak intermolecular forces |
| bromine, iodine | example of large dispersion force |
| molecules that are three-dimensionally symmetrical | example of nonpolar molecules |
| dipoles cancel out | molecule is symmetrical - nonpolar |
| lone pair on a central atom | make molecule asymmetrical - polar |
| bent and trigonal pyramidal | are always polar |
