Students will investigate electromagnetism by building their own classroom-made electromagnets and testing how changing the number of wire coils affects magnetic strength. Using an iron nail, insulated wire, a battery, and paper clips, students observe how electric current creates a magnetic field and how increasing coils strengthens that field. Through repeated trials, data collection, averaging, graphing, and a CER, students discover the relationship between coil turns and magnetic force while building core lab and engineering skills.

Learning Targets

• Plan and carry out a controlled investigation with repeated trials
• Measure electromagnet strength by counting lifted paper clips and calculate averages
• Graph class data to compare how coil turns affect magnetic strength
• Construct a CER explaining the relationship between coil number and magnet strength using magnetic field concepts
• Identify variables, maintain controls, and improve test consistency

What’s Included

• Teacher Guide

Setup diagrams, safety notes, battery-use guidelines, and clear background explanations of electromagnetism. Includes guidance for standardizing coil wrapping, contact time, battery connections, and paper clip testing to ensure fair comparisons.

• Student Packet

Hypothesis prompt, variables chart, step-by-step build/setup instructions, 3-trial data table per coil setting, average calculations, comparison table, graphing task, and structured CER response.Class totals chart, bar/line graph template (“Average Paper Clips Lifted vs Coil Turns”), labeled axes, and a caption prompt requiring students to identify which coil setting produced the strongest electromagnet using numerical evidence.

• Class Data & Graphing Pages

Class totals chart, bar-graph template (“Average Distance vs Nozzle Diameter”), labeled-axes lines, and a caption prompt requiring students to identify which nozzle produced the greatest thrust using numerical evidence.

• Analysis & Answer Key

Expected patterns (more coils → stronger magnet), sample data, reasoning examples, common error sources, and a full model CER paragraph grounded in magnetic field and current concepts.

• Rubric

Assesses experimental design, data accuracy, graph quality, CER strength, and teamwork/safety — fully aligned with middle-school science practices.

Why Teachers Love It:

• Low-prep & inexpensive — just nails, wire, batteries, and paper clips
• High engagement — students love seeing “invisible” forces in action
• Builds core lab skills: variables, controls, measuring, averaging, graphing
• Strong engineering + physical science crossover
• CER requires real evidence-based reasoning, not guesswork
• Perfect for stations, STEM days, electricity units, or sub-friendly lessons

➡️ You can get this STEM as well as all my other ones in this series inside my STEM Investigations Growing Bundle. As more labs are added, the price will increase. CLICK HERE to have a look

Best For

Physical Science (electricity & magnetism), engineering design, lab skills, graphing, CER writing, forces & fields, STEM challenges, or sub-friendly hands-on lessons.

Materials Needed

Iron nail (same size per group), insulated copper wire, D-cell battery or AA battery pack, paper clips (identical size), electrical tape, scissors or wire strippers, student packet (included). Optional: timer, safety goggles.

Estimated Timing

1 class period for build → testing → data collection → class graph

Add 20–30 minutes for CER writing, discussion questions, and improvement proposals

➡️ You can get this activity inside my STEM Investigations Growing Bundle.

I also have the following STEM Labs in My Store:

• Blow Cup Challenge STEM Lab
• Paper Table STEM Lab
• Pendulum STEM Lab
• Parachute STEM Lab
• Catapult STEM Lab
• Paper Airplane - Angle of Attack STEM Lab
• Bottle Flip STEM Lab
• Paper Helicopter STEM Lab
• Yeast Balloon STEM Lab
• Balloon Lift Design STEM Lab
• Candy Combustion Calorimetry STEM Lab
• Marble Ramp: Height vs Average Speed STEM Lab
• Clean Water Filtration STEM Lab
• Beetle Genetics STEM Lab
• Adaptations by Design - Extreme Environments STEM Lab
• Newton's 1st Law of Motion STEM Lab - Penny and Index Card - Inertia Test
• Newton's 2nd Law of Motion STEM Lab - Balloon Rocket
• Newton's 3rd Law of Motion STEM Investigation - Thrust vs Nozzle Size
• Electromagnet - Coil Turns vs Magnetic Strength — STEM Investigation

NGSS alignment

MS-PS2-3, MS-PS2-5 (forces & interactions, electric and magnetic forces)

Practices: Planning & Carrying Out Investigations; Analyzing Data; Using Mathematics & Computation; Constructing Explanations; Argument from Evidence

Assessment

Use the included rubric to score environment understanding, adaptation quality and plausibility, scientific accuracy, CER strength, and class data/graph work.