Earth Science - Rock properties; Inquiry Process - Observation, evidence, and reasoning to understand (6th -8th Grade)

Contents

Overview

This investigation explores rocks, their properties, how the rock's properties are a result of how the rocks were created (rock cycle).
Properties of minerals.

Earth Science - Related rock properties and how they were made

(what science says - enduring understanding, big ideas, generalizations)

The rock cycle describes how solid earth changes when rocks at the earth's surface weather, form sediments that are buried, then compacted, heated, and often recrystallize into new rock. Eventually, those new rocks may be brought to the surface by movements in the mantle and cycle continues.

Related concepts and facts

  • Rocks are composed of earth materials - sand, silt, humus (leaves, plant parts, animal parts, microorganism), gravel, rocks ...
  • Rock properties include luster, hardness, color, mass, density, crystals and if present their size,

Outcome

Describe how properties of rocks are the results of how they are formed.

Specific outcomes

  1. Observe and record observations of rocks different properties (color, hardness, crystals, grainy, small, luster).
  2. Describe rock properties of size, shape, color, texture, hardness, grainy, density, luster,
  3. Compared rock properties and group rocks by similar properties.
  4. Describe how rock properties are determined by the way the rock was made.

Inquiry - Processes - evidence, models, explanations - system, order, and organization - observation, properties, classification

Observations of an objects properties can suggest what materials were used to make it and how it was made.

Related concepts and facts -

  • Objects have many properties.
  • The properties an object has are determined by the way the object was made.
  • Observations of the properties of objects can suggest the materials used to make it and the different ways it was created.
  • A classification system can be used to group similar objects (rocks) by their similar properties into similar histories or similar ways of creation.
  • Observations can be used to provide evidence to create reasons for cause and effect.

Outcome

Identify properties/ characteristics of an object and suggest what materials were used to make them and the process used to make them.

Specific outcomes -

  1. Identify materials and the properties that make rocks.
  2. Suggest procedures that can be used to create rocks with certain properties/ characteristics.

Activities to provide sufficient opportunities for students to attain the targeted outcomes.

Possible Activity Sequence

  1. Observe different rocks
  2. Draw and record observations with possible explanations as to similarities and differences.
  3. Invent different properties of rocks luster, hardness, crystallization, limestone content,
  4. Invent how different properties of rocks suggest how they were created.
  5. Review the rock model, use two or three sample rocks from each group and explain how the properties of each suggest how each was created.
  6. Invent how a food product could be used as a model or analogy for each kind - Rocky Road Fudge as Edible sedimentary rocks, Brownie as ...
  7. How are rocks formed on other planets?

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Pedagogical ideas

Focus questions - What is a rock? What are the properties of rocks? From what are they made? How are they made?

Exploration

Activity 1

Materials:  rocks including granite, igneous, limestone, sedimentary, gneiss, metamorphic; Rocky Road Fudge, plastic knives, hand lenses

Instructional procedure

  1. Students observe rocks from a collection that represents the three ways rocks are created.
  2. Sort the rocks into three groups. (sedimentary, metamorphic, and igneous)
  3. Provide a magnifying glass and challenge students to think about how each of there three kinds could have been created.

Activity 2

  1. Share student drawings and records of their observations
  2. List properties of different rocks
  3. Share possible explanations as to similarities and differences. ask if they could describe a procedure for how each of the three kinds of rocks are created.

Activity 3

Identify different properties of rocks and find or invent a test for different properties - scratch test for hardness, acid test for limestone,

As properties are identified add them to the lab charts for each of the three kinds of rocks.

Conduct a scratch test on the different rock samples

Procedure

  1. Try scratching the different rocks with plastic knives, or scratch glass with the sample.
  2. How do the hardness of rocks vary?

Conduct some test for limestone on the different rock samples

The Effect of Acid on Limestone
Materials: rocks with limestone, chalk, seashells, vinegar (clear), clear plastic cup (10oz.), small pieces of rock (other than limestone)
Procedure

  1. Ask the students what will happen when the chalk is added to the vinegar.
  2. Have students pour 4-5 oz. of vinegar into plastic cups.
  3. Have students to place a piece of chalk into the vinegar.
  4. Allow the acid to react with the chalk and observe at 15-30 minute intervals.
  5. Allow the student to view the chalk the next day.
  6. Ask students to present their finding to the class.
  7. Review how acid rain can be damaging to building over time.

Activity 4

Continue to observe the rocks and list properties on the tables. If haven't, describe the kinds of crystals that are in each of the different kinds.

Begin to Invent how different properties of rocks suggest how they were created and add that information to the tables.

Activity 5

Review the rock model, use two or three sample rocks from each group and explain how the properties of each suggest how each was created.

Activity 6

Invent how a food product could be used as a model or analogy for each kind - Rocky Road Fudge as Edible sedimentary rocks, Brownie as ...

Materials:  rocks including granite, igneous, limestone, sedimentary, gneiss, metamorphic; Rocky Road Fudge, plastic knives, hand lenses

Edible Rocks

Materials: Samples of rocks (granite, igneous, limestone, sedimentary, gneiss, and metamorphic), several large pieces of rocky road fudge, butter knives, hand lenses

Procedure:

  1. What is the earth composed of? Answer: (igneous, metamorphic, and sedimentary) Show them examples and let them use a hand lens to investigate.
  2. Ask the students to list the properties of the rocks. Discuss the similarities and differences.
  3. Point out to the students that some rocks are actually a mixed variety of several different types of rocks, called conglomerates. These rocks are generally sedimentary rocks that contain several types of rocks cemented together.
  4. Have each student obtain a sample of the rocky road fudge.
  5. Ask the students cut through the sample at various points, loosening the various "rocks" held in the "conglomerate."
  6. Have the students record their observations.
  7. Ask the students how the conglomerate rocks compared to the three types of rocks they observed.
  8. Ask the students what they observed about the "rocky road fudge" rocks and ask them to compare it to actual conglomerates.
  9. Ask where each different component of the fudge represents a different type of mineral (or rock).

Activity 7

Ask students if rocks on other planets might have been created the same as rocks on Earth or if there might be other ways.

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Assessment ideas

 

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Lab Notes

Rock properties related to their creation.

Rock name Rock properties How it could be created
1    
2    
3    
4    
5    
6    

 

Conclusions

Three categories of Rocks and their properties

Sedimentary
Rock Rock properties How it could be created
1.    
2.    
3.    
4.    
5.    

 

Metamorphic
Rock Rock properties How it could be created
1.    
2.    
3.    
4.    
5.    

 

Igneous
Rock Rock properties How it could be created
1.    
2.    
3.    
4.    
5.    

 

 

Dr. Robert Sweetland's Notes ©