Mystery Substances: Properties of Matter Investigation (Part 1/2)

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Objective

SWBAT describe, identify and quantify matter using physical and chemical properties.

Big Idea

Mystery liquids and powders to identify? Toxic? Flammable? Who knows until you test and identify matter samples of unknown composition.

Introduction

Who dunnit!? What is it? Science mysteries - in this case using mystery powders or liquids - give students a way to apply their understanding of properties of matter to a real-world problem.

In this lesson, students explore physical and chemical properties of matter through stories, demonstrations and investigations with the objective of using properties of matter to identify different types of matter. This investigation is a precursor lesson to helping students meet the Matter and its Interactions performance indicator: Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred. (MS-PS1-2).

While students conduct this investigation to produce data to serve as the basis for evidence that meet the goals of the investigation (SP3), they analyze and interpret data to provide evidence for phenomena (SP4) and apply scientific ideas, principles, and/or evidence to construct, revise and/or use an explanation for real-world phenomena, examples, or events (SP6). Throughout this process, students explore how properties of matter are related to the structure of matter and that structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used (CCC). Also, students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure (CCC).

The Properties of Matter Investigation series of lessons is a scientific inquiry investigation taught over the span of several days. To help manage the magnitude of this activity, you will find the project split into 2 parts.

  • Part 1 (this lesson) includes the ENGAGE and EXPLORE/EXPLAIN components of the lesson; Time: 1-2 50-minute lessons or equivalent block period. 
  • Part 2 includes the EXTEND and EVALUATE components of the lesson; Time: 2-3 50-minute lessons or equivalent block periods.

Engage

25 minutes

In order to ENGAGE students in this lesson, I use two strategies:

1) First, we read a picture book called: The Paper Skyscraper: The Technology of Materials. This book provides clues based on properties of matter to help students identify a type of matter. For example, a clue might be, "It is found in books but not in computers." Follow-up clues could include, "It is flexible or it is thin or it is organic." Each of the clues helps students identify the type of matter (paper) using different properties of matter (flexible, thin, organic). While reading the book together, students hear relevant vocabulary words used in repetition: matter, property of matter, identify, characteristics, physical property of matter and chemical property of matter. These words are not written into the book, but it is important to use them, so students start to understand the scientific vocabulary necessary for the investigation.

2) Second, now that students have been introduced to the term "property of matter" and have an understanding that properties of matter describe matter, in pairs, students brainstorm as many properties of matter as they can think of on the Properties of Matter Investigation Student Handout. Students share these properties of matter with the class to create a class list of properties. To further engage students, I ask students if they would like to play a super-exciting game called...The Properties of Matter Game! (otherwise known as 20 Questions). For rules of the game, visit this 20 Questions Rules website. As we play, we add to our list of properties of matter. For example, if a student asks, "Is it red?", we write down color as a property of matter on our list.

Both of these ENGAGE activities serve the purpose of activating students' wealth of knowledge about describing objects and formalizing that understanding in terms of scientific terms and scientific process.

Teacher Note: The Paper Skyscraper is out of print, but the clues pages could be created or recreated easily in a PowerPoint or Slides presentation. Here is an example page from the book: Paper Skyscrapers Example Page.

Explore/Explain

65 minutes

The EXPLORE stage of the lesson is to get students involved in the topic so that they start to build their own understanding. To help students explore properties of matter, students complete two activities.

The first activity is designed to help students formalize their conceptual understanding of properties of matter and differentiate between physical and chemical properties. During this activity, students use resources (textbook or online resources like: Physical and Chemical Properties of Matter or Chemistry Basics) to complete the comparison chart on page 1 of the Properties of Matter Investigation Student Handout.

This stage of the lesson presents a great place for a quick formative assessment. While students complete this activity, active questioning helps students EXPLAIN (communicate what they have learned so far and figure out what it means). For more on the importance of using probing questions during this part of the lesson, read this section's reflection: Conceptual Sticky Points - Resolving Difficult Concepts. The final question in the comparison chart --

What is the difference between an intensive (characteristic) property of matter and an extensive property of matter? Why are intensive properties more useful?

...is a great higher-order thinking question for students to analyze. Depending on the level of understanding that is gauged, through questioning students, this question can act as an extension or be used later (after investigation and discussion) as a way to summarize student understanding of why some properties are more useful when identifying matter than others. After a quick review: Properties of Matter Investigation - Student Work,  Properties of Matter Investigation Notes is a clean copy of the notes, which is appreciated by students.

For the second part of this EXPLORE and EXPLAIN stage, students participate in a series of demonstrations. For Parts I and II, I use a tissue. Students observe physical properties and complete the first data table. For the second data table, a discussion of the tests we could perform to discover its chemical properties leads us to testing and observing the tissue in terms of its reactivity with oxygen, water, acid (vinegar), iodine, and oxygen in the presence of a flame (flammability). This video shows a student demonstrating this process:


Now that we've fully explored the tissue, for Part III, students observe glycerin's physical properties and we test chemical properties again. To encourage scientific practice around planning investigations, we conduct a simple experiment comparing the time the tissue burns with and without glycerin. With glycerin, the tissue will burn for a long time, which connects to a real world application about which common chemicals we could use to start a fire if we were lost in the wild. Students are surprised to hear that glycerin, Chapstick and petroleum jelly can all be used to get a fire burning!

Continue on to Part 2, which includes the EXTEND and EVALUATE components of the lesson; Time: 2-3 50-minute lessons or equivalent block periods.