LabLearner—The Science of Learning
LabLearner—The Science of Learning

Teacher Portal:

Weathering and Erosion

Investigation 1 – PreLab

 

 

 

 

 

 

 

Back to Investigation 1

ZERO-IN

Italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that weathering and erosion are the two main ways that Earth’s rocky surface is molded and changed. Together they create and reveal marvels of nature from boulders crashing down mountainsides to sandstone arches in the desert to jagged cliffs along the shore. 

BRANCH OUT

Remind students that erosion control specialists plan soil management or conservation practices, such as crop rotation, reforestation, permanent vegetation, contour plowing, or terracing, to maintain soil or conserve water.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Questions:

  • How are physical and chemical weathering different? Rocks are physically weathered by breaking them into smaller and smaller pieces. Rocks are chemically weathered when compounds in the rock react chemically with another chemical.
  • How do physical and chemical weathering combine to weather rocks? By breaking rocks into smaller pieces, physical weathering exposes more of a rock’s surface to chemical weathering. The combination of the two speeds the overall process of weathering.

Note: These questions are located in students’ SDRs at the beginning and end of the Investigation.

Note: These are succinct responses to the Focus Questions and are placed here for your reference at this time. Fully developed responses to the Focus Questions can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

  • Rocks consist of different elements and minerals in different proportions resulting in rocks being different.
  • Physical weathering occurs when rocks are broken into smaller pieces.
  • Force is required to break rocks into smaller pieces.
  • Physical weathering of rock occurs due to the following:
    • freezing of water in cracks in a rock,
    • forcing of rocks apart by growing tree roots,
    • day/night temperature fluctuations that cause rocks to crack,
    • loss of the thin surface of rocks exposing surfaces underneath, and
    • gravity causing rocks to fall from heights resulting in their breakage.
  • Chemical weathering occurs when elements and minerals in rocks react in a chemical reaction with chemicals from the environment.
  • Since all rocks are composed of different elements and minerals, not all rocks are subject to the same chemical weathering nor to the same extent of chemical weathering. 
  • Carbonic acid is a particularly significant chemical that causes chemical weathering.
  • Carbonic acid is formed by the reaction of atmospheric carbon dioxide and water or by the reaction of carbon dioxide produced by roots and water in the soil.

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  • Assess students’ prior knowledge and their understanding of the Background by asking them to recall the answers to the following questions.
    • What is weathering?
    • Why is it called weathering?

Note: Students will formulate answers to these questions after they have completed the Investigation.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

LEARN THE LabLearner LINGO

The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • physical weathering
  • chemical weathering
  • rocks
  • minerals

Note: Definitions to these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

  • Explain to students that they will investigate the physical and chemical weathering of marble and the mineral, calcium carbonate that marble contains.
  • Complete the Recall section in students’ SDRs.
  • Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
  • After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.

HOMEWORK

Tell students that they should review the Investigation in preparation for the Lab.