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