SWBAT prove that the mass/weight of matter is conserved, even when the temperature of matter changes.

In this lesson, students investigate how the heating of matter (ice) affects the mass. Then, students draw conclusions and construct a graph using the results of their investigations.

**Inquiry Based Instructional Model**

To intertwine scientific knowledge and practices and to empower students to learn through exploration, it is essential for scientific inquiry to be embedded in science education. While there are many types of inquiry-based models, one model that I've grown to appreciate and use is called the FERA Learning Cycle, developed by the National Science Resources Center (NSRC):

1. Focus

2. Explore

3. Reflect

4. Apply

A framework for implementation can be found here.

I absolutely love how the Center for Inquiry Science at the Institute for Systems Biology explains that this is "not a locked-step method" but "rather a cyclical process," meaning that some lessons may start off at the focus phase while others may begin at the explore phase.

Finally, an amazing article* *found at Edudemic.com, *How Inquiry-Based Learning Works with STEM, *very clearly outlines how inquiry based learning "paves the way for effective learning in science" and supports College and Career Readiness, particularly in the area of STEM career choices.

**Unit Explanation**

In this unit, students will begin by exploring the properties of matter. Then, the class will investigate the mass of matter before and after physical and chemical changes by conducting investigations and constructing graphs.

**Summary of Lesson**

Today, I open the lesson by discussing which has more mass: ice cubes in a bag or the water in the bag after the ice melts. Students then explore how heating matter (ice) affects the mass. At the end of the lesson, students reflect and apply their new understanding of the mass of melting ice by drawing conclusions and constructing graphs.

**Next Generation Science Standards **

This lesson will support the following NGSS Standard(s):

5-PS1-2. Measure and graph quantities to provide evidence that regardless of the type of change that occurs when heating, cooling, or mixing substances, the total weight of matter is conserved.

**Scientific & Engineering Practices**

For this lesson, students are engaged in Science & Engineering Practice:

Science & Engineering Practice 3: Planning and Carrying out Investigations

Students conduct an investigation by controlling variables, making observations, and measuring data.

To relate ideas across disciplinary content, during this lesson I focus on the following Crosscutting Concept:

Crosscutting Concept 4: Systems and System Models

Students analyze the components and interactions within an open system (open bag of ice) and closed system (closed bag of ice).

**Disciplinary**** Core Ideas**

In addition, this lesson also aligns with the following Disciplinary Core Ideas:

PS1.A: Structure and Properties of Matter

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. A model showing that gases are made from matter particles that are too small § to see and are moving freely around in space can explain many observations, including the inflation and shape of a balloon and the effects of air on larger particles or objects. (5-PS1-1)

The amount (weight) of matter is conserved when it changes form, even in transitions in which it seems to vanish. (5-PS1-2)

**Choosing Science Teams**

With science, it is often difficult to find a balance between providing students with as many hands-on experiences as possible, having plenty of science materials, and offering students a collaborative setting to solve problems. Any time groups have four or more students, the opportunities for individual students to speak and take part in the exploration process decreases. With groups of two, I often struggle to find enough science materials to go around. So this year, I chose to place students in teams of two or three! Picking science teams is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Each desk group has about six kids, so I simply divide this larger group in half or thirds.

**Gathering Supplies & Assigning Roles**

To encourage a smooth running classroom, I ask students to decide who is a 1, 2, or 3 in their groups of three students (without talking). In no time, each student has a number in the air. I'll then ask the "threes" to get certain supplies, "ones" to grab their computers, and "twos" to hand out papers (or whatever is needed for the lesson). This management strategy has proven to be effective when cleaning up and returning supplies as well!

20 minutes

**Matter Unit Lapbooks**

To provide students with a method to keep track of their research and thinking during our unit on matter, I followed these steps to create lapbooks for each student.

1. I folded each side of a file folder inward to create a booklet that opens from the center: File Folder.

2. Next, I made copies of Lapbook Templates on colored paper (purple, yellow, green, and orange). I made sure to have enough copies so that each student would have 4 graphs, 6 research notes, 8 investigations, 18 vocabulary words (9 sets of 2 words), and the 4 pictures. I also copied the Other Research Pocket onto blue card stock paper so that students would have a place to put loose papers.

3. Then, I stapled the templates into each lapbook: Inside the Lapbook.

4. Before starting our unit on matter, I asked students to help personalize their lapbooks. Students used a glue stick and tape to secure the blue research pockets on the back (Student Research Pocket Example). Then, they decorated the cover:

- Student Cover Example 1
- Student Cover Example 2
- Student Cover Example 3
- Student Cover Example 4
- Student Cover Example 5
- Student Cover Example 6
- Student Cover Example 7
- Student Cover Example 8

Creating these lapbooks helps build excitement and student ownership!

**Recognizing Students**

During yesterday's lesson, Changing the Shape of Matter, one of my teams of students wondered if ice and water would have the same mass: Students Proposing the Next Investigation. I begin today's lesson by recognizing this team and asking them to share their question with the rest of the class. Taking the time to honor these students is important as I want to continually encourage students to question the world around them and to seek answers - like true scientists!

**Class Discussion **

I pose the question to the rest of the class: *What if we have a bag of ice and the bag of ice melts. Will the bag of water have more or less mass than the bag of ice? *

At first, I ask students to turn and talk about this question so that they can gather their thoughts prior to a whole-class discussion: Students Discussing the Mass of Water & Ice.

The class discussion that follows is quite powerful and insightful: Class Discussion. I love listening to students try to make sense of science using what they already know:

- I know that water evaporates when it is heated. Due to this evaporation, some water will escape and the water will have a lower mass than the bag of ice.
- I know that water vapor in the air will collect on the outside of the cold bag of ice. Due to condensation, the bag of water will have a greater mass.
- I know that ice expands. The ice will take up more space, so it will have more mass.
- I know that ice floats. This means it must be lighter than water and have less mass.
- I know that ice is a sold. Solids are heavier than liquids because their molecules are more packed together.

It will be great for students to explore this concept further with an investigation!

40 minutes

**Getting Ready**

To prepare for today's investigation, I set out the following items on the counter:

- 10 Balance Scales (1 for each team)
- Labeled Bags (1 bag of per team)
- 8 Ice Cubes in Each Bag

*Today, each group will be given a bag of ice. What question should we investigate? *It doesn't take long for a student to ask today"s investigative question: Developing an Investigative Question.

**Investigation Template**

The class begins to complete a new investigation template in their lapbooks (Question & Observations (Before).

Question: How does the heating of matter (ice) affect the mass?

Observations (Before): Students draw a diagram of a bag of 8 ice cubes. They observe that the ice cubes are starting to melt. We also discuss the importance of having a close system so that no water or air can escape.

We also create a Data Table so that students have a place to record the results of their investigation. Students agree that they would like to measure the mass of the ice, then the mass of water and ice (partly melted/heated), and the mass of water (completely melted ice).

After students measure the mass of the bag of ice, I gather all team bags and place them in the microwave. After the bags of ice are partially melted, I call groups over by color to make sure they get their original bags. Students return to their desks and measure the mass of the bags. Then, we repeat this again. This time I microwave the bags until the ice is completely melted!

Teacher Note: I used sandwich bags for this investigation. I would recommend freezer quart bags to prevent leaking!

**Monitoring Student Understanding**

Once students begin working, I conference with every group. My goal is to support students by asking guiding questions (listed below). I also want to encourage students to engage in Science & Engineering Practice 7: Engaging in Argument from Evidence.

- What patterns have you noticed?
- Why do you suppose ____?
- What have you found so far?
- Has your thinking changed?
- What evidence do you have?
- How did you decide _____?
- What conclusion can you draw about ____?

**Student Conferences**

Here, Conferencing with a Group, a student explains why she thinks the water will have a greater mass.

During this conference, students verbalize their investigation findings: Group Measuring the Mass. These three students were placing all of their focus on the investigation instead of conversing!

Here, Guiding Students to the Correct Result, this team of students found that the bag of ice, bag of water/ice, and bag of water all have a mass within a few grams. I try to guide these students to see that the mass of all three are about the same.

30 minutes

**Sharing Findings**

Now that students have built meaning and understanding by observing, questioning, and exploring, it is important to provide students with the opportunity to share their findings. For this reason, I invite students to discuss their results as a class: Class Discussing Results. This is an important conversation to have before students write their investigation conclusions. Otherwise, some students might conclude that there was actually a change in mass when ice melts when this change was due to inaccurate scales, placement of the bag/mass weights on the platforms, or leaking bags!

**Drawing Conclusions**

I invite students to use their data and our class discussion to write the conclusions to their investigations. Here are a few examples of completed investigations: Student Investigation Example and Student Investigation Example 2. Many students volunteered to share theirs out loud with the class: Drawing Conclusions. I love how this student takes his thinking one step further to discuss the air molecules in ice: Open vs Closed Systems.

**Graphing**

According to NGSS Standard 5-PS1-2, 5th grade students are expected to "measure and graph quantities to provide evidence that regardless of the type of change that occurs, the total weight of matter is conserved." For this reason, I ask students to complete a graph template in their lapbooks to represent their findings.

We discuss how to label the x-axis with "Contents of Bag" and the y-axis with the "Mass." I then remind students how to determine the scale of their individual graphs using the highest data collected. For example, if their highest data point is 124 grams, they want to make sure that the scale counts by a number that allows them to graph up to 124 grams. Most students love graphing and can't wait to begin!

Here are a couple examples of student graphs: