| A | B |
|---|
| weathering | the breaking down of rock on the surface of the Earth usually by the force of water, wind, or ice |
| erosion | the movement of weathered particles by water, wind, or ice |
| deposition | the process in which materials that have been eroded are dropped in a new place |
| landform | a natural structure found on the surface of the Earth |
| glacier | a huge piece of ice that slowly moves across the surface of the Earth and remains frozen during the entire year |
| fault | a crack in the Earth's crust |
| earthquake | the shaking of the Earth's crust caused by large pieces of rock underneath the surface moving against each other |
| volcano | a mountain made from hardened lava, rocks, and ash that erupted out from underneath the Earth's surface |
| magma | melted rock below the Earth's surface |
| lava | magma that has flowed out onto the surface of the Earth |
| lithosphere | the rocky surface of the Earth |
| atmosphere | the pocket of air that surrounds the Earth |
| hydrosphere | all the water on the surface of the Earth and underground, including ice an water vapor |
| axis | an imaginary line running from the North Pole to the South Pole through the center of the Earth |
| rotation | the spinning of a planet or moon on its axis |
| orbit | the path one object takes around another object in space |
| tide | the rise and fall of the water level of the ocean near the shore that is caused by the pull of gravity of the moon |
| source | the place where something begins or comes from |
| sunspot | a less hot spot on the sun's surface that occurs for a short time |
| solar flare | an eruption of flame off of the sun's surface |
| corona | the outer edge of the sun's atmosphere |
| solar energy | energy from the sun |
| wind | moving air |
| natural resources | materials in the environment that are useful to people |
| fuels | material burned to produce heat energy |
| nonrenewable resources | natural resources such as fossil fuels that will eventually be used up and can never be replaced |
| renewable resources | natural resources that nature can produce again such as trees, plants, water, oxygen, and soil |
| inexhaustible resources | resources that humans can use and never use up such as solar energy and wind |
| water cycle | the change of water from one state to another as it travels from the Earth's surface to the atmosphere and back |
| evaporation | the process of changing from a liquid to a gas, usually caused by energy from the sun |
| condensation | the process of changing from a gas to a liquid, such as water vapor changing into water |
| precipitation | water falling to the surface of the Earth in the form of rain, hail, sleet, or snow |
| transpiration | the process of water vapor leaving a plant and entering the atmosphere |
| soil | a material made up of tiny pieces of weathered rock |
| humus | decaying plant and animal material in the soil |
| loam | soil rich in nutrients that is good for plant growth |
| nitrogen cycle | the movement of nitrogen between organisms and the environment |
| decomposers | organisms that break down dead materials and wastes |
| sedimentary rock | rock formed when sediments are pressed together |
| igneous rock | rock formed when lava or magma cools |
| metamorphic rock | rock that formed when another kind of rock was squeezed and heated deep inside the Earth's crust |
| fossil | the remains of a plant or animal that lived long ago |
| comet | a ball of ice and dirt that orbits the sun |
| meteor | a small rock that burns as it enters Earth's atmosphere |
| asteroid | a large rock in outer space |
| galaxy | a group of stars |
| constellation | a group of stars that ancient peoples thought formed a picture in the sky |
| astronomer | a scientist who studies bodies in outer space |
| climate | the usual weather in a place |
| air pressure | the weight of the air pressing on everything in the environment |
| barometer | a device that measures air pressure |
| humidity | water vapor in the air |
| precipitation | water falling to the Earth |
| nimbus clouds | rain clouds |
| front | the place where one air mass meets another air mass |
| air mass | a large pocket of air |
