| Term | Definition |
| Evaporation | The process of changing from a liquid state to a gas |
| Condensation | The process of changing from a gas to a solid |
| Precipitation | a process in a chemical reaction which causes solid particles to become separated from a liquid |
| Sublimation | The process of changing from a solid to a gas |
| recharge site | an area where water is entering the aquifer |
| zone of saturation | aquifer material that is filled with water |
| aquifer | a body of water underground that holds water |
| aquitard | a slab of impervious surface at the bottom of an aquifer that does not allow water to go through |
| recharge zone | the area above an aquifer where surface water seeps ino the ground and refills the aquifer |
| plume | the spread of groundwater pollution |
| permeable | the type of surface that does allow liquids to pass through |
| well | something to bring water out of the ground |
| impermeable | the type of surface that does not allow liquids to pass through |
| geological cross section | the type of map that shows different material levels beneath the earth's surface |
| water table | the top of an aquifer |
| clay | what a aquitard is made of |
| zone of aeration | aquifer material that contains mostly air |
| permeability | he ability of water to move through earth materials |
| porosity | the volume of open space between earth materials |
| ground water | water found under the earth's surface |