Activities and Extensions in the Developing a Model of Magnetism Unit

The following table shows the names and brief descriptions of the activities1 and the homework extensions in the ‘Developing a Model of Magnetism’ unit, which is the first unit in the Magnetism and Static Electricity module.  There are also links to the small and large class versions of two of the activities and the associated homework extension for one of them. 


Activity or
Extension #


Brief Description

UM Act 1

Modeling and the Mystery Tube

Students propose models of how strings are connected inside a tube, using only the evidence of what happens when certain strings are pulled.  This introduces them to the process of how models are developed, tested and revised.

UM Act 2

Small class version
Large class version

Exploring Magnetic Effects

Students collect evidence about what kinds of materials are attracted to a magnet, and how a magnetized nail (one rubbed a special way with a magnet) affects an unmagnetized nail and another magnetized nail.  They also learn about how magnetic poles are labeled, and the Law of magnetic poles (opposite poles attract, likes repel).

UM Ext A

Exploring the Region Around a Magnet

Students use the PhET ‘Magnet and Compass’ simulation to study magnetic effects in the region surrounding a magnet.

UM Act 3

Small class version
Large class version

Developing a Model for Magnetism

Using evidence from the previous activity, students construct their first model of magnetism (which is often a separation model, where the act of rubbing a nail with a magnet causes either N and S, or Plus and Minus, entities to separate to the two ends of the nail). They then make predictions about what would happen if their magnetized nail is cut into two pieces, test their predictions, and revise their model as necessary.

UM Ext B

Evaluating Magnetism Models

Students are presented with some models that other (hypothetical) groups claim can explain certain phenomena, and they are asked to evaluate whether such claims are valid.

UM Act 4

Better Model for Magnetism

Students perform a series of experiments, the results of which support a tiny magnets alignment model of magnetism.  [Inside of the nail are randomly oriented tiny magnets.  Rubbing the nail with a magnet causes the tiny magnets inside to align in one direction, making one end of the nail a North Pole and the other end a South Pole.] By the end of this activity, the small magnets model is generally the consensus model of the class.

UM Act 5

Explaining Phenomena involving Magnetism

Students use the small magnets alignment model to explain other magnetic phenomena that they have not observed before.

UM Act 6

Engineering Design: Is the US Loosing Its Edge?

Students analyze part of the design of a Maglev (magnetic levitation) train system and answer questions about it.

1The term ‘activity’ is used in the small class version of NextGenPET, and ‘lesson’ is used in the large class version.  For simplicity we will just use the term ‘activity’ to mean both.