Lesson 5 of 14
Objective: SWBAT define the three types of rocks and differentiate between how they form.
The Why Behind Teaching This
Unit 5 covers standards relating to Earth's Systems. It covers Standard 5-ESS2-1: Develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact. Students will be learning the difference between each of the systems, and ways that each of the systems interact to help make Earth what it is today. The other standard covered is Standard 5-ESS2-2: Describe and graph the amounts and percentages of water and fresh water in various reservoirs to provide evidence about the distribution of water on Earth.
Modeling will be an important component of this unit. Students will be modeling layers of Earth, the water cycle, land forms, and more. The unit begins with an overview of all the systems, then each system is taught in isolation. As each new system is covered, how it depends on or interacts with the previous systems will be addressed. In addition to the end of unit assessment, there will also be a culminating activity where groups build a model to demonstrate how 2 of the systems interact. Connections to several previously covered standards will also be made throughout this unit.
This specific lesson covers standard 5-ESS2-1 because it provides information about the geosphere and begins to lay the foundation for how the systems interact. In later lessons, we will be covering weather which plays a big role in the creation of sedimentary rocks.
The goal of this lesson is for students to be able to identify the three types of rock and describe how they change from one type to another.
Students will demonstrate success on this lesson goal by correctly answering questions while modeling the rock cycle.
Preparing For The Lesson:
- Three rock samples for each group: one igneous, one sedimentary, and one metamorphic
- A copy of the Comparing Rocks Information Sheet for each group
- A copy of the Rock Cycle Foldable for each student
- A copy of the Rock Cycle Foldable Diagram Inserts for students who need that modification
- A copy of the Rock Cycle Game Directions to place on the overhead and review with the class
- A copy of the Rock Cycle Game for each group along with a dice, several small rocks for game pieces, a set of Igneous Game Cards, Metamorphic Game Cards, and Sedimentary Game Cards for each group
- A bag of mini marshmallows, a bag of chocolate chips, a box of graham crackers, a microwave
You do not need any additional materials for this section as this will only be a review.
Three Types Of Rocks
To begin the lesson today, I provide each group with 3 rocks (one igneous, one metamorphic, and one sedimentary, but I do not tell them this). I also provide them with a copy of the Comparing Rocks Information Sheet and instruct them to draw a picture of each rock and then describe its appearance in words. All groups have the same rocks so I hold up one of the rocks and tell all groups to make that rock number 1 on the sheet, then I hold up another rock and tell them to make that rock 2, and the last rock will be rock 3. It is easier to make sure all groups have the same rocks for each number when it comes time to discuss what they have recorded. While groups share their descriptions for rock one, all other groups can compare what they had for the same rock.
After about 6 minutes of working, I ask groups to share the descriptions they have for each rock. The descriptions for the rocks were all very similar. For the igneous rock, most groups put that it was glassy, black, smooth, sharp edges. For the metamorphic rock groups had gray, smooth, flat, layers. For the sedimentary rock groups had that it was multicolored, bumpy, rough, and some even put that it looked like it was made of a bunch of different rocks.
I then tell them that rocks are formed from two or more different minerals (we just learned about minerals in the previous lesson). Each of the rocks you have were formed in a different way. Does anyone have any ideas on how these rocks were formed? Students learned about rocks in 4th grade so they do have some ideas. They are able to tell me that the black, glassy rock is an igneous rock and that it formed from a volcano. They are also able to tell me that the bumpy, multicolored rock is a sedimentary rock and was formed from a bunch of other rock pieces. They knew the third rock was the other kind but could not remember the name, or how it formed.
Why Begin the Lesson With this Activity
By providing the students with rocks to observe before teaching them about the rock cycle, I am giving them the opportunity to identify some of the differences for themselves. I purposely selected rock samples that demonstrate the common characteristics of each type. For example, I selected a metamorphic rock that has crystals, a sedimentary rock that you can clearly see the different layers, and an igneous rock that is black with holes from where it solidified quickly with gas bubbles still in it. When I begin teaching them about the rock cycle and I mention these characteristics they will be able to relate it to the observations they just made.
Another reason I began with this activity is because the students learned about the rock cycle in fourth grade and I want to see what they remember. I want to see if they are able to name the rocks they are given. Can they recognize them as igneous, metamorphic, and sedimentary? By doing the quick review I was able to see that they do remember the terms igneous and sedimentary and how both form but do not remember metamorphic. This helps guide my instruction through the lesson as I know I need to focus more on metamorphic rocks.
Rock Cycle Foldable
I collect the three rock samples and give each student a copy of the Rock Cycle Foldable that has been prefolded for them. They glue the foldable into their science notebook as I glue a copy in my science notebook and place it on the overhead as a model for students. Having my notebook on the overhead as a model is helpful to the ESE students who struggle with writing and spelling. Students who are absent also have a resource to copy from when they return to school.
There are pictures of three rocks and arrows on the front cover of the foldable. We begin by labeling each type of rock as I describe how they are formed.
- Sedimentary rocks can contain fossils such as the picture of the rock at the top. These rocks form from other rocks being broken (weathered) into small pieces (sediments) and then combining with plant and animal matter (the reason they can have fossils) to get cemented to form new rock. These rocks can either have layers of different types of sediment, or can be noticeable pieces of sediments stuck together.
- Metamorphic rock is formed from heat and pressure. Heat from inside the Earth and from the movement of plates producing friction. That heat, along with the pressure from layers above, cause rock to change. Metamorphic rock can have crystals from being heated and could have flattened layers from the pressure.
- Igneous rock has been formed from magma melting surrounding rock, cooling, and then hardening into new rock. This type of rock is often black from being burned, can have holes in it from cooling with air bubbles trapped, and can also contain crystals or have a glassy appearance from the melting and cooling.
After labeling each type of rock, I draw a little picture next to each one to help students remember how they form. I draw some small sediments next to sedimentary, layers of the Earth pressing down, as heat from within the Earth presses up next to metamorphic, and a volcano next to igneous.
Next, we fill in information in the arrows on how one type of rock can change into another. I question the students to see what they think will go in the arrow. This helps them see that for any rock to become igneous, it has to melt and cool, it doesn't matter if it is metamorphic or sedimentary. For any rock to become sedimentary, it must be weathered and sediments cemented together to form new rock. And for any rock to become metamorphic, it must go through heat and pressure.
How It Looks in the Real World
On the inside of the foldable, we diagram what the rock cycle looks like in action. We draw a volcano with magma at its center. We draw rain and wind weathering the igneous rock that formed near the volcano. Sediments being carried to a nearby pond where it settles to the bottom and is cemented together to form sedimentary rock. After many years, that sedimentary rock is pressed closer to the center of the Earth and gets heated where it is transformed into metamorphic rock. We are discussing what is happening as we diagram the entire process. I provide the ESE students with a copy of the Rock Cycle Foldable Diagram Inserts that have been precut and placed in Ziplock baggies. Having the written part already printed and cut for them allows them to focus more on the discussion taking place as opposed to copying.
Playing the Rock Cycle Game
I place a copy of the Rock Cycle Game Directions on the overhead. I go through the directions with the whole class and model on a game board how to move. I leave the directions on the overhead for students to refer to.
I provide each group with a copy of the Rock Cycle Game, small rocks to use as game pieces, a die, the Igneous Game Cards, the Metamorphic Game Cards, and the Sedimentary Game Cards. Groups play the game for the next 15 - 20 minutes. I circulate once in a while to listen to answers and to ensure the game is being played correctly.
Making Rock Cycle S'mores for a Formative Assessment
While groups are playing the game, I call them over one group at a time to make rock cycle s'mores. This is a fun way for me to assess student understanding. I ask them questions as we make the s'mores so that I can see which students know the types of rock and how they change into the other types.
I begin by giving each student several mini marshmallows and several chocolate chips. What part of the rock cycle would these small pieces represent? Sediments
I have the students smash it all together to make a ball (this gets a little messy because the marshmallow gets sticky, have hand wipes available). What type of rock does this model, now that the sediments are stuck, or cemented together? Sedimentary.
What would have to happen to our sedimentary rock to make it change to an igneous rock? It would have to be melted and cooled. What would have to happen to it to make it a metamorphic rock? It would have to go through heat and pressure.
We are going to change our sedimentary rock into metamorphic. I have the students apply pressure to their ball of marshmallow and chocolate chips by smashing it with their hand. We discuss how pressure from their hand also produced heat which has caused the marshmallow and chocolate chips to get even stickier.
Now we have a flattened metamorphic rock. What would have to happen to get it to become an igneous rock? It would have to be melted and cooled. How could it change into a sedimentary rock? The rock would have to be weathered and the sediments cemented together to form a new rock.
We are going to change it to igneous rock. We do not have magma to melt our rock so we will use a microwave. Students place their smashed marshmallow and chocolate chip ball on top of a graham cracker and heat it in the microwave. It melts in less than 20 seconds. I have them take out their treat and place another graham cracker on top before taking it to their seats to enjoy.
You can see in the video of complete rock cycle s'more activity that I shorten this process for some groups, based on what I have heard in small groups during the game. If I have a good idea that some groups understand the process I ask fewer questions. If there is a group that I know may be struggling, I would spend more time and go into more detail with the activity. I would also call on specific students in the group to answer instead of just allowing one person to speak for the whole group. Here is another video of complete rock cycle s'more activity which I ask some different questions with.
Why Model With Food
We completed a diagram of the rock cycle on our foldable so why students model the process again? Having them answer questions while modeling the rock cycle with food allows me to check for understanding on an individual basis. I walked them through completion of the diagram in our foldable, now can they apply what they learned to a model of their own? Although I call a whole group over (3-4 students together), I am asking each student individual questions and if a student answers incorrectly his peers can help. I am able to get a pretty good idea of who has grasped the concepts.
Although the modeling could be done with clay or something else, I use food because students love to work for food. It helps with classroom management during the game because I call groups over to make the s'mores based on who is playing the game quietly and correctly, with no arguing. Everyone wants to come make the s'mores so they are focused on the game trying to be the next group to come over.
Game Winners and Review
All groups clean up the game and determine who the winners are. I reward the winners with tickets (our classroom incentive). As I collect the game materials, I review today's lesson by asking the questions below. I call on students who struggled with the questions being asked during the rock cycle s'mores activity.
- Which of Earth's systems are rock part of? geosphere
- What are the three types of rocks? Igneous, metamorphic, and sedimentary
- Which type can have fossils in it? sedimentary
- Why is this the only type to have fossils? Sediments are cemented with plant and animal matter that can contain remains
- Which type of rock is found near a volcano? Igneous
- How do metamorphic rocks turn into sedimentary rocks? Weathering breaks the rock into sediments
- What can weather rock into sediments? Wind and Water
- How do metamorphic rocks turn into igneous rock? Magma melts the rock and then in cools and hardens into new rock
- Why can both metamorphic and igneous rock have crystals in them? Because the heat causes crystallization
- What is the difference between rocks and minerals? minerals are naturally occurring substances that are the same throughout and rocks are made up of two or more minerals