Lesson A: Electromagnetism

Focus

Whilst observable phenomena often provide the starting point for new scientific understandings, scientists can use abstract ideas and analogies to develop new theoretical models.

By using an analogy to link a poorly understood area of science with a well understood area of science scientists are able to draw upon old resources to solve new problems.

Scientists need to be able to recognise those analogies that are useful. Useful analogies might link areas of science previously considered as separate. Useful analogies can also generate predictions that can be tested.

Rationale

The lesson aims to develop students understanding of the role of theoretical models in science. In particular that models:

• can be developed using creative analogies;
• may contain features that do not correspond directly with the real world;
• may provide links with other areas of science;
• generate testable predictions.

Activities

This lesson consists of three activities.

Activity A1

This activity is set in the contexts of the electromagnetic 'catapult' effect and the kinetic theory of gases. Working as a whole class, and then in small groups, students place statements from these contexts on a spectrum ranging from ‘observable phenomena/objects’ to ‘abstract ideas’.

Activity A2

Using the resources provided, the teacher presents the main features of Faraday's ideas about magnetic field lines and Maxwell's model of magnetic vortices. Working in pairs students then discuss their responses to a set of questions about these two models before the teacher takes feedback and gives the appropriate responses for each of the questions.

Activity A3

Students use the kinetic theory of gases to make a prediction that there is a minimum temperature