| A | B |
| tetrahedron | geometric shape of the water molecule |
| hydrogen bond | weak bond between the hydrogen of one water and the oxygen of another |
| maximum number of hydrogen bonds between water molecule | four |
| adhesion | the attraction of water to other substances such as glass or zylem vessel walls |
| cohension | the attraction between water molecules |
| surface tension | due to cohesion; the "film" that forms on top of water |
| capillarity | the ability of water to move up fine tubes |
| polarity | water has slight positive and negative regions in spite of the fact that it is neutral |
| specific heat | the amount of heat needed to change the temperature of one gram of a SUBSTANCE 1 degree C |
| calorie | the amount of heat needed to change the temperature of l gram of WATER 1 degree C |
| heat | total kinetic energy |
| temperature | average kinetic energy |
| Heat is released | when hydrogen bonds FORM |
| Heat is absorbed | when hydrogen bonds BREAK |
| evaporative cooling | heat is absorbed when water evaporates |
| hydronium ion | H3O+ |
| pH scale | measure of the hydrogen ion concentration of a solution |
| [H+] 10-5 | [OH-] 10-9 |
| acid | substance that increases the hydrogen ion concentration in a solution |
| buffer | weak acid base pair that stabilizes pH of a living system |
| base | substance that reduces the hydrogen ion concentration of a solution |
| acid precipitation | pH below 5.6 |
| sulfur dioxide and nitrogen dioxide | main causes of acid precip |