Mystery Powders

Contributor
Utah Educator Network KIrstin Reed
Type Category
Instructional Materials
Types
Instructor Guide/Manual , Lesson/Lesson Plan
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

Students investigate the physical properties of five powders to determine their identity. In a follow up investigation, students observe changes to the powders when a drop of iodine is added to determine whether or not new matter has been made.

 

Intended Audience

Educator
Educational Level
  • Grade 5
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

5-PS1-3 Make observations and measurements to identify materials based on their properties.

Clarification Statement: Examples of materials to be identified could include baking soda and other powders, metals, minerals, and liquids. Examples of properties could include color, hardness, reflectivity, electrical conductivity, thermal conductivity, response to magnetic forces, and solubility; density is not intended as an identifiable property.

Assessment Boundary: Assessment does not include density or distinguishing mass and weight.

This resource was not designed to build towards this performance expectation, but can be used to build towards it using the suggestions provided below.

Comments about Including the Performance Expectation
While the lesson identifies "evaluate evidence that indicates a physical change has occurred" as the standard objective, the lesson is written in a way that lends itself to students identifying a given powder based on which liquid it reacts with. Introducing additional tests such as color and solubility in water would include more properties to use as evidence that have been explicitly listed as possible properties to assess in the clarification statement.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Shifting the lesson to encourage student driven planning and conducting of the property investigation moves the lesson beyond a traditional "cookbook" lab experience. During part one, students should collaboratively explore how someone might discern one powder from another. The observations gathered might then be used to analyze and interpret data or engage in argument from evidence about which powder is which. Including one or more liquids with which none of the powders react further enriches the investigative experience during part two. Students must not be allowed to use "taste" were allowed would be that the substance known as salt tastes "salty" and the substance known as sugar would taste "sweet". Tasting "unknown substances" is not advised in science classrooms at any age level.

Disciplinary Core Ideas

This resource was not designed to build towards this disciplinary core idea, but can be used to build towards it using the suggestions provided below.

Comments about Including the Disciplinary Core Idea
This learning experience might be made richer by having students weigh the powders before and after the substances are mixed. This will provide students ample data to explore the concept of conserved mass, but only if such reactions are performed in closed containers such as ziplock bags. Attending to precision in both mathematics and language is also practiced in this lesson. Through recorded observations about what is happening in the chemical reaction and numerical value computation.

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
Through multiple interactions between the powders and various liquids added, students will observe and be able to argue with evidence the creation of new matter in a gaseous state. This investigation also provides an opportunity for students to learn about safe handling of materials and equipment. Students should all wear googles during this work.

Crosscutting Concepts

This resource was not designed to build towards this crosscutting concept, but can be used to build towards it using the suggestions provided below.

Comments about Including the Crosscutting Concept
Students might write an explanation of what happens when you add iodine to the mystery powders that includes the causal relationship in their explanation. The teacher might asks students questions about the investigation that address cause and effect such as: What caused the reaction during the investigation. Please explain the results of the investigation in terms of cause and effect.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Without implementing some of the tips provided this resource is limited. Making these changes can move this resource from limited to strong. To make this lesson more relevant for students teachers should consider contextualizing the experience through a plausible such as a crime investigation or other scenario where unknown substances must be identified at the peril of their teacher or society as a whole!

  • Instructional Supports: Aside from background knowledge for the teacher on physical and chemical changes there is little in the way of instructional supports.

  • Monitoring Student Progress: There is a suggestion that students keep a journal to record student questions and learning throughout the unit. Some handouts for students are provided but require modification for improved alignment to the three dimensions of NGSS.

  • Quality of Technological Interactivity: - none -