Lesson 20

Changing Matter: Day Two of Nahari Has The Solution!

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SWBAT identify substances based on their properties.

Big Idea

How do scientists use the properties of matter to identify substances? Students identify the crystals that result from their evaporation test, and use their knowledge of the properties of matter to try to categorize a new substance.

Setting Up the Investigation

This is Day Two of a Two Day Lesson.  Click here for Changing Matter:  Day One of Nahari Has The Solution!

Connection to The Next Generation Science Standards

In this investigation, students explore the  Disciplinary Core Idea of Structure and Properties of Matter -  that matter of any type can be subdivided into particles that are too small to see, but even then the matter still exists and can be detected by other means. (5-PS1-A); and use the Crosscutting Concept of Scale, Proportion, and Quantity  - natural objects exist from the very small to the immensely large (5-PS1-1), and Energy and Matter - energy can be transferred in various ways and between objects (5-PS3-1).

Please Note:  The Lexile Level for What's The Matter Plaid Pete? - Lab Scenario Sheet Lesson 18 is 890 (5th Grade Range is 740 - 1010).

The Preparation Time for This Investigation is approximately 10 minutes.

Materials Needed:

One copy for each student of the Safety Contract

One copy for each student of What's The Matter Plaid Pete?- Lab Scenario Lesson 19

One copy for each student of What's The Matter Plaid Pete?- Lab Sheet Lesson 19 (copy as separate pages - as you will hand out at different times)

One set of What's The Matter Plaid Pete?- Word Wall Cards Lesson 20 for the Word Wall, and paper copies for each student

What's The Matter Plaid Pete? - Crystals - Lesson 20

One graduated cylinder for each team

Safety Goggles for each student

Gloves for each student

One plastic cup with holes and a coffee filter per team (or other system to filter material)

3 additional plastic cups per team (For Cups A, B, & C)

1 vis a vis pen per team to mark cups

Salt for each team (Substance 1)

Corn Meal for each team (Substance 2)

1 flat lid with a lip deep enough to pour the water from Cup A into (I also taped a piece of black construction paper to the outside bottom of this lid.  It will make the salt crystals easier to observe)

1 materials tub for each team

Materials for "Oobleck" on Day Two:

Cornstarch (8 oz. per team / for "Oobleck")

Food Coloring (Optional - for "Oobleck")

1 Large mixing bowl per team


Focus & Motivation

15 minutes

Introduce Salt Crystals.

My students came running into the room this morning and made a bee-line for the dishes that they had left to evaporate yesterday.  There were choruses of "Ooohs and Ahhs" as they observed the salt crystals in the dishes.  They immediately wanted to know what had happened, and why.  There were a few students offering their conjectures.  I tell my students that they will have to wait until Science, and they can barely contain their enthusiasm.

When the appointed time arrives, I ask my students, "What was in the mixture that you put into the dishes yesterday?  I accept a few responses, - with some students stating that it was salt and some that it was sugar.  They have lots of experience with these ingredients at home, and since salt and sugar have a similar appearance, it is not surprising that they would think it was one or the other.  Yesterday when they mixed substance 1 into the cup into the cup with water and filtered it, I heard many comments stating that, "Oh it's salt," or "No, it's sugar."

I have team leaders retrieve their evaporation dishes from the window.  I show the What's The Matter Plaid Pete? - Crystals - Lesson 20 Presentation to students and ask them to compare the pictures to what they observe in their dishes.  

I explain that what they are seeing are "crystals" - a solid form of a matter where the particles are arranged in a regular, repeating pattern.  I show the example of sugar crystals, and salt crystals.  I point out that the difference between the sugar crystals in the picture and salt crystals, is the distinctive X shaped pattern in the center.  They get their measuring glasses ready and examine the crystals.  I instruct my students to turn and talk to their partner, and see if they can find evidence for which substance they can make a claim for. 

I call on a few student pairs, and they claim that the crystals are salt crystals, providing as evidence, the distinctive X shaped pattern on each crystal.  I am pleased that they have seen this.  I confirm that yes, the solute that was dissolved in the solvent (water) was indeed salt.  

Review Lesson Objective & Success Criteria

Note:  Consistent with the Sheltered Instruction Observation Protocol, I am now includinga language objective with each lesson.  These objectives were derived from the Washington State ELP Standards Frameworks that are correlated with the CCSS and the NGSS.

I review the lesson objectives and success criteria that was shared yesterday:

Learning Objective:  I can compare and contrast mixtures and solutions.

Language Objective:  I can use academic language to compare and contrast.  [ELP.4-5.7]

Success Criteria:  I can make a claim to correctly identify a substance as a mixture or a solution, and provide supporting evidence in my Science Notebook.

Claims & Evidence

I ask my students if we have enough to make a claim about whether the substance in Cup A was a mixture or a solution.  I have my students turn and talk in their teams, construct a claims and evidence chart, and then list their claim and their evidence.

I claim that the substance in Cup A was _______.

My evidence for this is ________________.

I then call on teams to share out and we have a class discussion.  We compare the criteria for a solution and a mixture that we learned about yesterday.  Students recognize that they had to do an evaporation test to separate the ingredients of Cup A, so it must be a solution.  Finally, they all agree that the substance in Cup A was a solution and that our evaporation test provided evidence of the material left behind.

I say, "Well, now that we have some understanding of mixtures and solutions.  I think it's time we looked into this "Oobleck" substance that has Seth so puzzled."

Team Activity

25 minutes

 Constructing Oobleck

I project the following instructions on How to make Oobleck.  I also provide a printed copy for each team, and a materials tub with all needed materials.  Students work together in their teams to mix the ingredients as directed.  And of course, since this is a very messy activity - and very fun for students - I am figuring that it will take about 5 minutes to construct it, and another 15 or so (at least!) to explore.  I give an extra caution about exploring appropriately and that the Oobleck needs to stay on the work surface!

Open Exploration

I tell my students to pay careful attention to the properties of this mystery substance.  I call on them to think about all they have learned in this unit on the properties of matter, and compare that to this new substance they are encountering.  I tell them I will give them about 15 minutes to explore, and then we will need to clean up and have a class discussion. This is quite an engaging activity!

As students are exploring and discussing this interesting substance in their teams, I move between my groups, prompting them to use the vocabulary they have learned, and asking them questions, such as: What have you learned about the properties of matter that you could apply to this substance?  What category would you place it in?  In this Video Clip, this student is connecting what she has learned with something she has seen on TV.  She is learning to connect her experiences with the content and vocabulary she has learned.

Exploration time ends all too soon, but I know that students won't focus on the discussion if they have this in their hands.  So, I give the signal to clean up.  I tell my students that we have some new vocabulary to add to our collection, and then a class discussion to engage in.

Vocabulary Instruction

10 minutes


Consistent with the 5E Model of Instruction - The majority of vocabulary instruction in my classroom occurs during the "Explain" or instructional stage.  This ensures that students have the experiential activities that will allow them to connect new vocabulary terms to conceptual understanding.

I present the four words from the What's The Matter Plaid Pete?- Word Wall Cards Lesson 20 using the same instructional routine outlined in a previous lesson.  In this particular case, I will give considerably more support, as students will not be as adept with these four words as they would with others.  They are new to both their listening and speaking vocabularies:

  1. Say the word to students.
  2. Ask students to repeat the word at least 5 times.  For example, I will say, "Say it to the window.  Say it to my hand.  Say it to the door.  Say it to the ceiling."
  3. I say the word in context.  For example, I will say, " The position the plants were placed in was one of the controlled variables in the video."  
  4. I will then randomly call on a student to use the word in a sentence, giving successive prompts to assist them, if needed.

Science Notebooks

I also use the same Science Notebook routine as was used in previous lessons:

After introducing the words, I again demonstrate for students how to make a three column table with rows for each of the eight vocabulary words.  I model for them in my own Science Notebook how to write the word in the first box, a non-linguistic (e.g. picture) representation of the word in the second box, and work with the class to generate an example sentence for the first word in the third box.  Students cut out their copies of the cards and place in the envelope, which they glue on the page behind their table.  They will finish sentences for the remaining seven words either for homework, or for seat-work later.  


Reflection & Closure

15 minutes

Academic Discussion

My students are becoming much more adept at using academic language in their discussions and I am looking forward to listening to their ideas.  I call them to the meeting area.  I say, "So, you have now had quite a bit of experience with different types and states of matter.  What kind of conjectures can you make about what this "Oobleck" substance is, and what evidence do you have to support your conjectures?

I then call on students to begin discussing their ideas.  I use the hand signals we have established to prompt them to elaborate and clarify, support with evidence, build onto other's ideas, and to paraphrase, and synthesize.  I have adapted these from the book, Academic Conversations:  Classroom Talk that Fosters Critical Thinking and Content Understandings by Jeff Zwiers.  I post the sentence stems from the book so that my English Language Learners can easily access them.

I am now actively "coaching from behind" with my English Language Learners.  As other students comment, and then call on a student who has raised their hand to respond to their comment, I lean in behind my English Language Learners and use a whisper voice to coach them into these conversations by providing prompts and sentence stems

They are discussing their ideas, and some students think "Oobleck" is a solid, while others think it is a liquid.  Some students think it is a mixture, while others think it is a solution.  After they have had an opportunity to discuss their ideas, I say, "I am so proud of all of you and your great scientific thinking.  Yes, this is a very perplexing substance.  And actually, if Nahari were here, I think she would tell you that "Oobleck" is actually something called a colloidal mixture."  I write out the words on my easel and tell students that a colloidal mixture is a mixture where the particles of one substance, in this case cornstarch, are suspended throughout another substance, in this case - water.  In a solution, the particles would dissolve, but in a colloidal mixture, the make-up of the particles does not allow them to dissolve.

Just when you think you have learned all about matter - there is always something new to learn!  Poor Seth - no wonder he was so confused!