| A | B |
|---|
| water | world's most important polar covalent compound |
| hydrophilic | water loving chemical--either polar covalent compounds or ions |
| hydrophobic | water hating chemicals--NONpolar covalent compounds |
| polar covalent bond | unequal sharing of valence electrons between a low & high electronegativity atom |
| nonpolar covalent bond | equal sharing of valence electrons between two atoms whose electronegativity is about the same |
| C-H bond | example of nonpolar covalent bond |
| O-H bond | example of polar covalent bond |
| partial negative charge | in a polar covalent bond, develops on the atom with higher electronegativity |
| partial positive charge | in a polar covalent bond, develops on the atom with Lower electronegativity |
| O atoms in water | these carry a partial negative charge since their electronegativity is higher |
| H atoms in water | these carry a partial positive charge because they have lower electronegativity |
| hydrogen bond | weak attraction (---) of Partial + H in one polar covalent molecule to a partial (-) N or O in another |
| cohesion | attraction of one water molecule to another water molecule |
| adhesion | attraction of a water molecule to an ionic substance or to a different polar covalent molecule |
| surface tension | force of attraction between water molecules at the surface, holding them together |
| capillary action | ability of water to climb walls of a thin tube made of polar covalent or ionic material |
| lower density of ice | the result of water molecules spreading out farther from each other in solid versus liquid |
| high heat capacity | water uses releases energy to make H bonds & absorbs energy when it breaks them, so water's temperature changes slowly |
| high specific heat | more heat is required to heat 1 g water than most small molecules, allowing water to stabilize earth temperatures |
| lipids | nonpolar covalent, hydrophobic biomolecules |
