| Term | Definition |
|---|---|
| Salt water and Fresh Water | Two types of water that cover the earth and are involved in the water cycle. |
| Water Vapor | Most water in the atmosphere exists as this invisible gaseous form. It can change into solid or liquid water. |
| Groundwater | Water that fills the cracks and spaces in underground soil and rock layers. This water is located within the rocks below the Earth's surface. |
| Transpiration | Process by which leaves in plants give off water in the form of water vapor. |
| Water Cycle | The continuous movement of Earth's water from the ocean to the atmosphere to land and back to the ocean. It is driven by the energy of the sun. |
| Condensation | Takes place when water vapor cools and changes into water droplets that form clouds in the atmosphere. Changes gas to liquid. |
| Evaporation | Takes place when water from the oceans and the Earth's surface changes into water vapor. Changes liquid to gas. |
| Precipitation | Rain, snow, sleet, or hail that falls from the clouds on to the Earth's land and oceans. |
| Percolation | The downward movement of water through pores and other spaces in soil due to gravity. |
| Runoff | Is precipitation that flows over land into streams and rivers. This water later enters the ocean. |
| Zone of Aeration | Once water seeps underground this is one of two zones that is considered the upper zone. |
| Zone of Saturation | Deeper zone underground where water collects. In this zone, spaces between rock particles are filled with water. |
| Water Table | The boundary where the Zone of Aeration and Zone of Saturation meet. |
| Aquifer | A rock layer that stores ground water and allows the flow of groundwater. |
| Porosity | The percentage of open space between rock particles in a rock layer. |
| Permeable | A rock's ability to let water pass through it. |
| Non-Permeable | Rock that stops flow of water is this. |
| Friction | Is a force that causes moving objects to slow down. Less of this allows water to flow more easily through the rock layer. |
| Spring | An area where groundwater reaches the surface or a place an aquifer meets the surface. |
| Well | A human made hole that is deeper than the level of the water table. |
