Weathering

acid

*any liquid with a pH lower than 7 on the pH scale; The lower the number on the pH scale, the stronger the acid is.* Normal rainwater has a pH of about 5.5, so it is considered a very mild acid. Lemon juice has a pH of about 2. Have you ever felt a burning sensation when you got lemon juice in a cut on your finger? The burning occurs because lemon juice is acidic.

oxidation

another form of chemical weathering

Which of these is the layer of solid rock that is found under all soil?

bedrock

How is igneous rock formed?

by cooling of magma or lava

Which type of rock forms from the evaporation of mineral-rich water?

chemical sedimentary

Which type of weathering occurs by the formation of a new substance which acts to break up rock?

chemical weathering

What type of sedimentary rock forms when particles of minerals and rocks are cemented together?

clastic sedimentary

fissures

cracks

humus

decayed organic matter

Expansion and contraction, with regard to weathering, are caused by rusting. T/F

false

If a rock becomes a metamorphic rock, no other changes in the rock cycle will occur. T/F

false

The breaking down and wearing away of the earth's rocks by the atmosphere is called oxidation. T/F

false

topsoil

made of sand, silt, and clay mixed with humus

What type of rock has changed from one type of rock to another?

metamorphic

What type of rock is slate?

metamorphic

chemical weathering

occurs when minerals in the rock react with water, oxygen, and acids in the environment

physical weathering

occurs when rocks break apart without changing their chemical makeup

crystals

solid objects that form when the atoms arrange in a regular dimensional pattern

bedrock

the layer of solid rock underneath soil

Which layer of soil contains humus?

topsoil

Lava flows and volcanic ash are examples of magma that has reached the earth's surface. T/F

true

oxide

when minerals combine with oxygen in the air or water

rock cycle

First, magma melts and is forced upward or into other spaces. Then the magma cools and forms an igneous rock. Weathering and erosion occur, and sediments are broken apart by chemicals or physical actions. The sediments are then moved by wind, water, or other means. They compact and cement together to form a sedimentary rock. The heat and pressure of mountain building can change the rock to metamorphic rock, and the cycle continues.

hydration

form of chemical weathering that occurs when certain chemicals in a rock combine with water, causing a chemical reaction

metamorphic rock

form when a rock changes form under extreme heat and pressure; EX: Coal turns into diamonds under extreme heat and pressure

clastic sedimentary

form when particles of minerals and rocks, called clastic, are compressed and cemented together to form hard sedimentary rock

igneous rock

formed when molten rock hardens and cools

carbonic acid

forms when carbon dioxide in the atmosphere reacts with water in the air or soil

extrusive igneous

forms when lava cools and hardens into rock on the earth's surface

sedimentary rock

forms when mineral fragments, such as small pieces of shells, soil, rocks, and dead plants and animals, settle on the earth's surface

Which type of physical weathering occurs when water seeps into cracks of rocks and freezes?

frost wedging

For metamorphic rocks, which forces allow for mineral growth and change within the rock?

heat and pressure

intrusive igneous

heat and pressure within the earth force movement of magma, causing some of it to go into cracks in other rocks

Which of these is the decaying organic substance that makes topsoil nutrient rich and is essential for plant growth?

humus

What type of rock is quartz?

igneous

Which type of rock is formed when magma forces itself into surrounding underground rock?

intrusive igneous

frost wedging

occurs when water gets into spaces or joints in soil or rock and then freezes; As water freezes, it expands. The ice expands the joint. When ice melts, the joint opens and allows more water inside. Then it refreezes. Even a hairline crack can become larger and larger until it breaks huge boulders apart.

leaching

occurs when water seeps into a rock, dissolving and washing away some of the minerals

What type of rock forms when material from dead plants and animals is deposited and hardens into rock?

organic sedimentary

exfoliation

peeling of large curved sheets from a rock; As each layer peels, the pressure of the underlying rock decreases, allowing the underlying rock to expand. Exfoliation occurs when the rock's joints are slightly curved, closely spaced, and parallel. Exfoliation most often occurs in granite and leaves behind dome-shaped rocks.

Which type of weathering occurs when only the size of a rock is changed?

physical weathering

weathering

process by which rock is decomposed and disintegrated due to exposure at or near the earth's surface

acid rain

produced from pollution; has a pH lower than 4.5;

chemical sedimentary

rocks form when minerals dissolve in water

organic sedimentary

rocks form when organic material from plants and animals is deposited and hardens into rock; EX: coal

geologists

scientists who study rocks and rock formations

Which type of rock is formed from the cementing of small pieces of older rocks, shells, soil, or dead plants and animals?

sedimentary