Soils, Rocks, and Landforms Unit: Investigation 1

Explain how water freezing in the rocks causes rocks to break apart

When water goes into the cracks and freezes, the water expands when it turns to ice. When it expands, it causes the cracks to get bigger and the rock eventually breaks.

calcite

a common rock-forming mineral in Earth's crust

basalt

a dark rock formed from cooling lava

acid rain

a form of precipitation containing acid, which forms when carbon dioxide gas in the air dissolves in water droplets; a form of chemical weathering

marble

a metamorphic rock formed when limestone is subjected to heat and pressure

soil

a mix of humus, sand, silt, clay, gravel, and/or pebbles

chemical reaction

a process in which two or more materials mix in a way that forms new materials

model

a representation of the features and actions of a natural system or process

conglomerate

a rock composed of smaller pieces like clay, silt, sand, gravel, and pebbles

limestone

a sedimentary rock made mostly of calcite

sandstone

a sedimentary rock made of sand particles stuck together

rock

a solid earth material made of two or more minerals

What is the main cause of chemical weathering?

acid rain

granite

an igneous rock that forms inside Earth

earth material

any natural resource that makes up Earth, including soil and water

humus

bits of dead plant and animal parts in the soil

What type of rock is most likely to react with acid, form crystals, and become chemically weathered? What mineral does a rock usually have in it that causes it to REACT with acid?

limestone. A rock that has the mineral calcite is likely to react with acid.

What are the two main effects of chemical weathering?

minerals in the rock change, the rocks can break apart

True/False: All soils have the same amount of humus in them.

False. Some soils can have more humus than other soils, depending upon where the soil is found.

True or False: All soils have the same types of rock materials in them

False. The true statement is that soil can be made up of many different types of rocks. For example, one soil could be made up of sand, gravel, and pebbles and another could be made up of clay, silt, sand.

What is abrasion?

Abrasion is when two rocks rub against each other, causing physical weathering of the rocks to occur.

How are chemical weathering and physical weathering the same?

Both cause rocks to break apart.

How is chemical weathering different from physical weathering?

Chemical weathering causes minerals to change in a rock and physical weathering just causes a rock to break.

freeze

to become hard or stiffened due to loss of heat

system

two or more objects that work together in a meaningful way

expand

when the volume of a substance increases or gets bigger

What is humus and what does it do for soil?

Humus is made up of dead plants and animals. It provides nutrients for the soil.

Weathering is the breakdown of rocks into smaller pieces. There are two main types of weathering, what are they?

Physical weathering and chemical weathering

Name two ways that one soil can be different from another soil

The first way is by the type of rocks in the soil (Example: one soil can have more pebbles and less gravel than another soil. The second way is by the amount of humus in the soil.

Name as many different types of rocks that can be found in soil.

pebble, gravel, sand, silt, clay

sand

rocks that are smaller than gravel, but bigger than silt; component of soil

gravel

rocks that are smaller than pebbles but bigger than sand; component of soil

silt

rocks that are smaller than sand, but bigger than clay

Abrasion typically causes rock to become _________________________ (smoother / bumpier) over time

smoother

erosion

the carrying away of weathered earth materials by water, wind, or ice

pebble

the largest category of rock pieces; component of soil

weathering

the process by which larger rocks crack and break apart over time to form smaller rocks

physical weathering

the process by which rocks are broken down by breaking and banging

chemical weathering

the process by which the minerals in a rock can change due to chemicals in water and air. Chemical weathering can cause rocks to break apart.

abrasion

the rubbing, grinding, and bumping of rocks that cause physical weathering

clay

the smallest category of rock pieces; component of soil