Lesson 19

Changing Matter: Day One of Nahari Has The Solution!

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Objective

SWBAT compare and contrast mixtures and solutions

Big Idea

What is a mixture? What is a solution? How do you tell the difference between the two? Students actively mix, filter, and evaporate, to add to their growing wealth of knowledge about the properties of matter.

Setting Up the Investigation

Connection to The Next Generation Science Standards

In this investigation, students explore the Disciplinary Core Idea of Structure and Properties of Matter -  When two or more different substances are mixed, a new substance with different properties may be formed (5-PS1-4) and the Crosscutting Concept of Scale, Proportion, and Quantity  - Standard units are used to measure and describe physical quantities such as weight, time temperature, and volume (5-PS1-4).

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 20 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 graduated cylinder for each team

Safety Goggles 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

10 minutes

Introduce the Scenario

Today, my students are excited to learn that they will be learning a bit more about Nahari - Seth's friend.  I hand out copies of What's The Matter Plaid Pete?- Lab Scenario Lesson 19 to each student. 

I again have parts highlighted, and students quickly decide who will be performing the reader's theater roles in their teams.  I find that this practice is working well for my students.  It is helping my English Language Learners access grade level text, and building fluency for some of my grade level readers who don't spend as much independent "time on the page" as I would like them to.  

I tell my students, "Hmmm . . . I know that Seth is pretty smart in Science, I am wondering what Nahari will be able to teach him.  This looks like a fun investigation!"

Share 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 share the lesson objectives and success criteria:

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.

Guided Exploration

30 minutes

Introduce the Investigation

I tell my students that today, we will be conducting an investigation in which they will be working with some "mystery ingredients."  Because the ingredients are unknown, they will need to take safety precautions and will need to wear safety goggles to ensure that the mystery ingredients do not get in their eyes or make contact with their skin.  (This catches their attention!).  

We have previously had a class discussion about safe handling of materials in the classroom, and have constructed a class poster about appropriate behavior and use of materials during science labs.  I have also sent home a Safety Contract that they were required to discuss with parents, and that had to be signed by both the parent and the student.  I emphasize that I trust them to follow correct procedures, and if they are unable to mange their behavior during Science investigations, they won't be allowed to participate.  The document, Science Safety:  It's Elementary! Has some great tips on Science safety procedures in the elementary school classroom.

Investigation Directions

I hand out What's The Matter Plaid Pete?- Lab Sheet Lesson 19 to each student.  I only hand out the first page, with Labs A and B on it.  I will hand out Lab C after the Instruction section of this lesson.  I make sure that they understand they are not to discard the liquid from the cup from Lab A (They will need it for Lab C!)  

I ensure that they understand exactly what they are supposed to do for Lab A and Lab B. I then allow my research teams to work for a few moments to assign jobs for the two labs.  As has been the case previously, they will not be allowed to go to the back table to retrieve their materials tub with the components for their investigation until they have shown me the plan for who will complete each task.  This is a Video Clip from a previous investigation where I am checking in with a team to review their plan before they begin.  

When they have complied with this step, I send the team leader back to retrieve the tub and they are allowed to begin.  I circulate between the teams, watching as they measure Substance 1 (salt) into their graduated cylinder.   Then they carefully measure and add the water, stirring to dissolve the mystery substance.  Then, they filter the contents of the cup.  As they finish Cup A, they are completing their models, and labeling their diagrams.  

Students then measure Substance 2 (corn meal) into their graduated cylinder.  They add water, and filter the contents of this cup as well.

I have a spot on the back table that is labeled for each team with a sticky note.  They place the cups there that they have labeled as Cup A and Cup B (according to the directions on the Lab Sheet).

As teams are finishing up, I tell them that now that they have had an opportunity to work with some "mystery ingredients" - it's time to find out what Nahari was trying to teach Seth about mixtures and solutions.  I ask students to get out their Science Notebooks and a pencil and get ready to take some notes.  (Bet you can't tell what time of year this lesson was taught!)

Instruction

25 minutes

Mixtures Video

I tell my students that we will be watching a short video that will give them some information about mixtures and solutions.  I tell them to listen carefully, as we will be collecting some notes.  

I play the following Scholastic video:  Study Jams - Mixtures

When the video finishes adding items to the "Summary" screen, I freeze the screen and ask students to turn and talk to their partner, and discuss the first bulleted item.  

  • A mixture is a physical combination of two or more substances that retain their own properties and can be separated.

I ask students to copy that note into their Science Notebooks.

I share that being "separated" means that the individual substances in a mixture can be easily separated either by putting them in different piles, as in the video, by allowing them to settle, and I give the example of oil and water, or by using a filter - as they did in their investigation today.  We add that note to the bulleted note that we have collected.

I follow this same procedure for the remaining three bullets.  

  • If you can see different substances in a mixture, it's called heterogeneous.
  • Mixtures can be solid, liquid, or gas.
  • If you cannot see the different substances in a mixture it's called homogeneous - (solution).  Solutions don't separate easily.  You can do an evaporation test.

 

I specifically insert the requirement that the word "solution" must be included in the final bullet.  (I have to rewind the video a bit and replay that section, as it is referred to in the audio, but not in the written text).  I also add the note that solutions are not easily separated, and that one way to separate the substances in a solution is through evaporation.  

This is an example of a student notebook page

Further Investigation

I ask my students if we have enough evidence to determine if the two mystery ingredients are mixtures or solutions?  

I call on student volunteers.  I have a few students that try to impulsively guess, but I redirect them back to their notes and the models they created in their Science Notebooks.  I want them to base their arguments from evidence.  They come to realize that we only have enough evidence to state that the mystery substance in Cup B was a mixture.  The filter that was used with Cup B contained material, providing evidence of a mixture.  This is what their models reflect.  However, there was nothing in the filter in Cup A.

When I question students to reexamine their notes, they come to the conclusion that they need to do an evaporation test.  I then hand out the 2nd page of the Lab sheet that has Lab C on it.  Students follow the directions and we place the dishes in the window sill to anxiously wait and see what will be there tomorrow when we arrive in the morning!