Mystery Material

By Michelle Daniel •

Grade Level	9th
Subject Area	Chemistry
Duration	30 minutes
Setting	Traditional classroom with large tables
Background Knowledge	Elements, Compounds, States of Matter, and Laboratory Rules and Techniques
Author	Michelle Daniel

Summary
In this lesson, students will participate in a hands-on engagement activity where they will use their observational skills as well as their background knowledge to identify a mystery material. Student’s prior learning includes knowledge about elements, compounds, states of matter, and laboratory rules and techniques. This activity links directly to a multiple day lesson about physical and chemical changes. Students will work on this activity in groups in order to simulate a real-world situation. In the real-world, scientists rarely research and investigate by themselves. It is important for students to learn how to work as a team and to build communications skills within those groups. After students have made their predictions about what the mystery material is, they will also be asked to identify what type of change they think occurs when water is added to it (physical or chemical) and why. This activity is intended to practice student’s observation and inference skills. It is also intended to practice student’s laboratory techniques. And, most importantly, this activity will serve as a fun and interesting inductive lesson where the students are the primary investigators. This lesson is relevant to students because the mystery material is a product that all of them have seen or used in their life time. Relevance is expounded upon by the fact that the mystery material is produced and used at Procter and Gamble, a company in the Cincinnati area that they all know.

Materials
• Latex gloves for each group • Containers of the mystery material (diaper crystals: sodium polyacrylate) -Recommendation: buy sodium polyacrylate in your local gardening store. Measuring cup filled with water for each group • Paper towels! • Mystery Material worksheets for each student

Objectives
1. Students will practice making scientific observations and documenting those observations. 2. Students will investigate the physical properties of a mystery material by recording observations of the mystery material before and after the addition of water. . 3. Students will know and understand the difference between a physical and chemical property through class discussion. 4. Students will make inferences through their scientific investigation and predict what the mystery material is. 5. Students will identify and understand the change (physical) that takes place through a guided class discussion. 6. Students will identify the mystery material based on their previous scientific knowledge and evidence from their investigation and observation. 7. Student will construct an investigation to determine the absorption capacity of the mystery material through the application their previous knowledge of scientific experiments and procedures and their comprehension of the concept of water absorption. 8. Students will be introduced to Chemical Engineering through a Career Sheet and see how this particular field relates to the mystery material.

Ohio Standards

Science

Standard: Physical Science

Benchmark C: Describe the identifiable physical properties of substances. Explain how changes in these properties can occur without changing the chemical nature of the substance.

Indicator 9: Investigate the properties of pure substances and mixtures (e.g., density, conductivity, hardness, properties of alloys, superconductors and semiconductors).

Standard : Scientific Inquiry

Benchmark A : Participate in and apply the processes of scientific investigation to create models and to design, conduct, evaluate and communicate the results of these investigations

Indicator 1 : Distinguish between observations and inferences given in a scientific situation

Indicator 3 : Construct, interpret and apply physical and conceptual models that represent or explain systems, objects, events or concepts

Indicator 6 : Draw logical conclusions based on scientific knowledge and evidence from investigations.

Standard : Scientific Ways of Knowing

Benchmark C : Describe the ethical practices and guidelines in which science operates.

Indicator 2 : Illustrate that the methods and procedures used to obtain evidence must be clearly reported to enhance opportunities for further investigations

Benchmark D: Recognize that scientific literacy is part of being a knowledgeable citizen.

Indicator 9: Investigate how the knowledge, skills and interests learned in science classes apply to the careers students plan to pursue.

Technology

Standard: Designed World

Benchmark E: Classify, demonstrate, examine and appraise information and communication technologies.

Indicator 1 : Describe the careers available in information and communication technological systems and the training needed to pursue them.

Math