| Term | Definition |
| atmosphere | a layer of gases surrounding a planet |
| axis | an imaginary straight line on which a planet rotates |
| barometer | a device or tool used for measuring air pressure |
| carnivore | a meat eating animal also known as a predator |
| conductor | a material that carries electricity well |
| consumer | an organism or animal that ingests other organisms or organic matter in a food chain |
| constellation | any of the 88 groups of stars as seen from Earth that represent animals, objects or mythological people |
| decomposer | an organism (like bacteria, worms, and fungi) that feed and breakdown dead organisms |
| evaporation | the slow changing of a liquid into a gas |
| herbivore | an animal that eats plants (like rabbit, deer, or squirrels) |
| insulator | a material that does NOT conduct electricity well |
| omnivore | an organism (like a bear or human) that eats plants AND animals |
| photosynthesis | the chemical process by which plants make their own food. Plants use light to convert carbon dioxide and water into carbohydrates. Oxygen is released during this process. |
| pitch | how high or low a sound is |
| producer | an organism that is able to make its own food (such as a green plant) and is a food source for other organisms |
| reflection | the bouncing of heat or light off an object |
| refraction | the bending of light as it moves from one material to another |
| revolution | the movement of an object around another object or point; the trip that a planet takes around the Sun |
| rotation | the spinning motion of a planet on its axis as it revolves around the Sun |
| telescope | an optical instrument used for making distant objects appear closer and larger; used for looking at objects in outer space |
| thermometer | a device or tool used to measure temperature |
| translucent | material allowing only SOME light to pass through |
| transparent | material that allows light to pass through |
| volume | the loudness of a sound |
| kinetic energy | the energy of motion |
| potential energy | the energy an object has because of its condition or position |
| rapid Earth processes | evidence of changes on Earth in such examples as volcanic eruptions, landslides, and earthquakes |
| slow Earth processes | evidence of changes on Earth in such examples as erosion, weathering, deposition, and mountain building |
| endangered | threatened with extinction |
| opaque | material that does NOT allow light to pass through |
