| Term | Definition |
| Weathering | ________ is a natural process that causes rock to change, breaks them down, and causes them to crumble. |
| Mechanical | ________ weathering breaks rocks into smaller pieces without changing them chemically. |
| mechanical | When ________ weathering occurs the small pieces of rock that break off are identical in composition to the original rock. |
| mechanical | Ice wedging is a type of ________ weathering. |
| Ice wedging | ________ ________ is the freezing and thawing process that breaks apart rocks. |
| expands | Ice wedging breaks apart rocks because water ________ when it freezes into ice. |
| Potholes | ________ in roads are formed because of ice wedging. |
| roots | Plant ________ can break apart rocks. |
| mechanical | When plant roots break apart rocks this is a type of ________ weathering. |
| Animals | ________ can break apart rocks when they tunnel and burrow through the soil. |
| mechanical | When animals tunnel and burrow their way through rock this is a type of ________ weathering. |
| Chemical | ________ weathering occurs when the chemical composition of rock changes. |
| carbonic acid | When water mixes with carbon dioxide from the air or in the soil ________ ________ is formed. |
| weak | Carbonic acid is a ________ acid. |
| chemically | Carbonic acid ________ dissolves the rock it comes in contact with. |
| acid rain | When carbonic acid forms in the atmosphere and falls to the ground as rain we called this ________ ________. |
| chemically | Plants can also ________ break down rocks by producing a plant acid called tannic acid. |
| Moss | ________ is a very short green plant that can grow on rocks and break them down chemically. |
| Oxidation | ________ is the effects of chemical changes caused by oxygen. |
| rust | When iron-containing materials such as steel are oxidized a chemical reaction causes the material to ________. |
| oxygen | Some rocks can be colored red or orange when iron-bearing minerals in them react with ________. |
| iron oxide | Even a tiny amount of iron in rock can combine with oxygen and form a reddish ________ ________. |
| iron oxide | Another name for rust is ________ ________. |
| rust | Another name for iron oxide is ________. |
| Soil | ________ is a mixture of weathered rock, organic matter, water, and air that supports the growth of plant life. |
| leaves | Organic matter includes decomposed ________, twigs, roots, and other types of organic material. |
| twigs | Organic matter includes decomposed leaves, ________ , roots, and other types of organic material. |
| roots | Organic matter includes decomposed leaves , twigs, ________, and other types of organic material. |
| five | There are ________ factors that affect soil formation. |
| Parent rock | ________ ________, slope of land, climate, time, and organisms are all factors of soil formation. |
| slope of land | Parent rock, ________ _____ ________, climate, time, and organisms are all factors of soil formation. |
| climate | Parent rock, slope of land, ________, time and organisms are all factors of soil formation. |
| time | Parent rock, slope of land, climate, ________ and organisms are all factors of soil formation. |
| organisms | Parent rock, slope of land, climate, time and ________ are all factors of soil formation. |
| topography | The slope of the land is also called ________. |
| Topography | ________ is the surface features of an area. |
| little | On steep hillsides soil has ________ chance of developing. |
| greater | In lowland areas where the land is flat soil has a ________ chance of developing. |
| deep | If rock weathers quickly, ________ soils develop. |
| shallow | If rock weathers slowly, ________ soils develop. |
| Tropical | ________ regions where the weather is warm and moist have lots of organic matter in the soil. |
| Desert | ________ regions where the weather is hot and dry have very little organic matter in the soil. |
| humus | When plants and animals die, decomposition by fungi and bacteria form a soil called ________. |
| Humus | ________ helps soil hold water and provides nutrients that plants need to grow. |
| less | As soils develop, they become ________ like the rock from which they formed. |
| Lichens | ________, organisms that consist of an alga and a fungus living together, can chemically breakdown rock. |
| grassland | Some of the best farmland is where ________ used to be. |
| Erosion | ________ is the wearing away and removal of rock or sediment. |
| gravity | Erosion occurs because ________, ice, wind, and water sculpt Earth's surface. |
| ice | Erosion occurs because gravity, ________, wind, and water sculpt the Earth's surface. |
| wind | Erosion occurs because gravity, ice, ________, and water sculpt the Earth's surface. |
| water | Erosion occurs because gravity, ice, wind, and ________ sculpt the Earth's surface. |
| Gravity | ________ is a force that pulls every object toward every other object. |
| center | Gravity pulls everything on Earth towards its ________. |
| downhill | Gravity causes water to flow ________ and rocks to tumble down slopes. |
| tumble | Gravity causes water to flow downhill and rocks to ________ down slopes. |
| Mass movement | ________ ________ occurs when gravity alone causes rock or sediment to move down a slope. |
| four | There are ________ types of mass movements. |
| Creep | ________, slump, rock slides, and mudflows are four types of mass movements. |
| slump | Creep, ________, rock slides, and mudflows are four types of mass movements. |
| rock slides | Creep, slump, ________ ________, and mudflows are four types of mass movements. |
| mudflows | Creep, slump, rock slides, and ________ are four types of mass movements. |
| Creep | ________ is the name for a process in which sediments move slowly downhill. |
| freezing | Creep is common where ________ and thawing occurs. |
| thawing | Creep is common where freezing and ________ occurs. |
| slump | A ________ occurs when a mass of rock or sediment moves downhill along a curve surface. |
| rock slide | During a ________ ________ layers of rock break loose from slopes and slide to the bottom of the slope. |
| mudflows | Where heavy rains or melting snow and ice saturate sediments, ________ can develop. |
| mudflow | A ________ is a mass of wet sediment that flows downhill over the ground surface. |
| glaciers | Over many years, the snow can accumulate to form large, deep masses of ice called ________. |
| weight | When the ice in a glacier becomes thick enough , its own ________ causes it to flow down hill under the influence of gravity. |
| erode | As glaciers move over Earth's surface, they ________ materials from some areas and deposit sediment in other areas. |
| deposit | As glaciers move over Earth's surface, they erode materials from some areas and ________ sediment in other areas. |
| two | There are ________ kinds of glaciers. |
| Continental | ________ glaciers in polar regions cove about ten percent of the Earth and are so large and thick that tye can bury mountain villages. |
| Valley | ________ glaciers are much smaller and are located in high mountains where the average temperature isn't warm enough to melt the ice sheets. |
| erosion | Continental and valley glaciers move and cause ________. |
| cirques | In mountains, valley glaciers can remove rock from the mountaintops to form large bowls called ________ and steep peaks called horns. |
| horns | In mountains, valley glaciers can remove rock from the mountaintops to form large bowls called cirques and steep peaks called ________. |
| till | The sediment deposited by glacier ice is called ________. |
| Till | ________ is a mixture of different-sized particles of rock, ranging from clay to large boulders. |
| outwash | Sand and gravel deposits laid down by glacier rivers is called ________. |
| size | Unlike till, outwash usually consists of particles of rock that are all about the same ________. |
| deflation | When ________ occurs wind leaves behind particles of rock too heavy to move. |
| Abrasion | ________ is a form of erosion that can make pits in rocks and produce smooth, polished surfaces. |
| runoff | Water the flows over Earth's surface is called ________. |
| Sheet | ________ erosion occurs when a thin sheet of water carries away loose grains of sediment. |
| Rills | ________ are small channels cut into the sediment at Earth's surface. |
| gullies | When rills widen and deepen they become ________. |
| Streams | ________ are the most important agent of erosion on Earth. |
| Streams | ________ shape more of Earth's surface than ice, wind, or gravity. |
| Deltas | ________ are areas where rivers enter oceans or lakes, the water slows and sediment is deposited. |