front 1 a force that exists between any two objects that have mass | back 1 gravity |
front 2 a system of objects that revolve around a star | back 2 solar system |
front 3 a pure substance that cannot be broken down into simpler substances by chemical reactions | back 3 element |
front 4 the ordering of sedimentary layers of rock with the oldest on the bottom and the youngest on top | back 4 superposition |
front 5 melted rock located beneath Earth's surface | back 5 magma |
front 6 a compound made of hydrogen and oxygen | back 6 water |
front 7 the study of Earth through the study of rocks, minerals, water, and other Earth materials, as well as through seismic waves and other natural phenomena | back 7 geology |
front 8 a nonrenewable resource formed from organic carbon due to the compression and partial decomposition of organisms | back 8 fossil fuels |
front 9 the innermost layer of Earth, made up mainly of iron and nickel | back 9 core |
front 10 something put together with materials that serves a purpose | back 10 structure |
front 11 the layer of solid rock between Earth’s crust and core | back 11 mantle |
front 12 the layer of rock that forms Earth's surface | back 12 crust |
front 13 to figure out what data or information means | back 13 analyze |
front 14 a drawing, object, or idea that represents a real event, object, or process | back 14 model |
front 15 the large, empty part of the universe that does not contain any matter | back 15 space |
front 16 a large, circular pit in the surface of a planet or other body in space usually formed when two bodies in space collide | back 16 crater |
front 17 Earth's crust, both beneath the oceans and continents, as well as the mantle and inner and outer core | back 17 geosphere |
front 18 the part of Earth which is composed mostly of rocks; the crust and outer mantle | back 18 lithosphere |
front 19 from a time before human history was recorded | back 19 prehistoric |
front 20 a piece of rock or metal from space that strikes Earth's surface | back 20 meteorite |
front 21 minerals in rock that can be extracted and used by people to make things | back 21 ore |
front 22 resources that are obtained from the earth | back 22 natural resources |
front 23 the process of reasoning by drawing a logical conclusion based on factual evidence | back 23 inference |
front 24 the study of the properties and behavior of bodies in outer space | back 24 astronomy |
front 25 the theory that a solar system evolves from a hot gaseous nebula | back 25 nebular hypothesis |
front 26 a length of time | back 26 period |
front 27 a body in outer space that orbits a planet; a natural satellite | back 27 moon |
front 28 a type of rock formed by gravity pressing fragments of other rocks and minerals together as they settle on land or under the ocean over a long period of time | back 28 sedimentary rock |
front 29 the information about Earth's history that can be gathered from fossils | back 29 fossil record |
front 30 a layer or line of rock above or below another body of rock | back 30 rock layers |