The Good, the Bad, and the Electromagnet

Mandek Richardson and James Cooper (under the advisement of Patricio Rocha, Dayna Martinez and Tapas K. Das)
Type Category
Instructional Materials
Experiment/Lab Activity , Lesson/Lesson Plan , Activity
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.



In this introduction to the concept of electromagnetism, students build and test two versions of electromagnets - with an iron core and without - and compare results.  They follow up by doing an experiment to test the effect of another, student-chosen, variable on the strength of their electromagnet. The site includes background reading for the student, student lab worksheets, a list of needed materials, and a list of vocabulary terms with definitions.  This introductory lesson may be best suited for students with no prior experience with magnetism or electromagnets.

Intended Audience

Educational Level
  • Middle School
  • Grade 8
  • Grade 7
  • Grade 6
Access Restrictions

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

Performance Expectations

MS-PS2-3 Ask questions about data to determine the factors that affect the strength of electric and magnetic forces.

Clarification Statement: Examples of devices that use electric and magnetic forces could include electromagnets, electric motors, or generators. Examples of data could include the effect of the number of turns of wire on the strength of an electromagnet, or the effect of increasing the number or strength of magnets on the speed of an electric motor.

Assessment Boundary: Assessment about questions that require quantitative answers is limited to proportional reasoning and algebraic thinking.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
Students compare data (number of metal staples picked up with two versions of electromagnets) in order to determine which electromagnet exerts the strongest force. They then devise and run their own experiment, changing one variable about the electromagnet to see what effect it has on the strength. The lesson uses the words “power” and “intensity” instead of the word “force” - a teacher will need to change that, and to ensure that students enter the lesson knowing what a force is. To fully address the idea about the strength of both electric and magnetic forces, students will need to understand the link between the two, and how the strength of one implies the strength of the other. The post-activity assessment suggests students possibly be allowed to increase the number of batteries; by encouraging this experiment, students could see more clearly the relationship between strength of electric force and strength of resulting magnetic force.

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
Students evaluate the difference between the two electromagnets in the experiment in order to determine which was more effective. This difference is meant to be a springboard for thinking about why they act differently, but students will need background knowledge to help them with this, as the actions of atoms and domains is not visible. The lesson includes a background information section, which could be shared with students after they are asked to share their own current thinking about why one of the electromagnets might have worked better than the other. During the assessment, students design and conduct their own investigation.

Disciplinary Core Ideas

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
The lesson assumes that students are familiar with the fact that magnets attract iron. This is a good place to watch out for the student misconception that magnets attract all metals. The lesson focuses on how the size of the force is affected by the composition of the electromagnet. A teacher can make the connection to charge, current and/or magnetic strength clearer by using the background information to help students understand why it is that one of the electromagnets was stronger than the other. Students can then use that information during the assessment, as they design and run their own experiment about a variable in electromagnet design.

Crosscutting Concepts

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
This concept is addressed in the background information, but will need to be shared with students during the discussion in step 14 of the lesson.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The lesson centers around phenomena involving electromagnets and their design. With use of the background information after the activity and before the assessment, this lesson can address a Practice, CCC, and portions of a DCI. The lesson does not address the core idea of repulsion. It is important to note also that students will be answering, not asking, questions about their data.

  • Instructional Supports: The activity begins with a concept familiar to students - magnetism - and sets up a simple comparison activity that will be accessible to students. Students engage in a practice in order to make sense of a concept. Differentiation is not addressed in the lesson plan, though opportunities may exist for a teacher to assign roles within a lab group, or encourage different groups to take on assessment variables with different levels of complexity, or to allow students to share their findings in written form vs. diagrams vs. orally.

  • Monitoring Student Progress: The lesson includes a worksheet, which is suggested as an embedded assessment. While the questions on the worksheet may offer a guide to students’ prior knowledge about magnetism, they do not address any aspect of the PI, CCC, DCI or Practice. The post-activity assessment will be most effective if students are equipped with background knowledge about how magnetism works. The post-activity assessment is merely a general statement about what the students should do, and does not include any pre-made guides, materials, supports, or grading rubric. The post-activity assessment is a popular engineering activity, so a web search will allow a teacher to find other sources for plans, scaffolding, etc to allow them to conduct the assessment activity.

  • Quality of Technological Interactivity: This lesson does not require technological interactivity.