| A | B |
|---|
| transparent | clear, letting light through so that things on the other side can be clearly seen |
| opaque | not letting light through, not transparent |
| buoyancy | ability for something to float |
| density | closeness, thickness, the amount of matter in a unit of volume |
| matter | anything that takes up space and has properties that you can observe and describe |
| mass | the amount of matter making up an object, mass is measured in grams and kilograms |
| solid | a form of matter that has a definite shape and takes up a definite amount of space |
| liquid | a form of matter that takes up a definite amount of space and has no definite shape |
| gas | a form of matter that does not take up a definite amount of space and has no definite shape |
| precipitation | water in the atmosphere that falls to earth as rain, snow, hail, or sleet |
| evaporation | the change of a liquid to a gas |
| condensation | when water particles change from a gas to a liquid |
| amphibian | a cold-blooded vertebrate that spend part of its life in the water and part of its life on land |
| mammal | a warm-blooded vertebrate with hair or fur that feeds milk to its young |
| reptile | a cold-blooded vertebrate that lives on land and has a backbone, an endoskeleton, and waterproof skin with scales or plates |
| ecosystem | the living and nonliving things in an environment and all their interactions |
| organism | a living thing that needs food, water, oxygen, and shelter |
| habitat | the home of an organism |
| galaxy | a group of billions of stars forming one system. The earth and sun are in the Milky Way |
| constellation | a group of stars that forms a recognized pattern |
| conductor | a material through which heat travels well |
| insulator | a material that is a poor conductor of heat |
| erosion | the wearing away of rocks and rock materials, as when glaciers leave distinctive features on the Earth's surface |
| loam | rich fertile soil; earth in which decaying leaves and other plant matter are mixed with clay and sand |
| silt | very fine particles of earth and sand carried by moving water |
| gravel | pebbles and pieces of rock that are larger than grains of sand. It is used for roads and paths. |
| peat | a king of turf, used as fuel after being dried. It is made from partly rotted moss and plants. |
| attracts | to draw to itself or oneself |
| repels | to force apart or away |
| barometer | in instrument used for measuring the pressure of air |
