Expansion/Contraction of Metals

Teachers' Page

Copyright 1999 by James P. Riser

Background info:

In this activity students will be comparing expansion and contraction rates for several types of metals. They will be working with fire and need to take necessary precautions. It will be wise to remind students that the metal being heated will remain hot for a few minutes after the flame is removed.

Goals - this activity was created to present my students with the opportunity to:

The specialized equipment needed is illustrated below:


A large sewing needle needs to have a copper wire pointer threaded through it and twisted around the needle eye.

The needle rests between the glass microscope slide and the metal bar being tested.

As the bar expands, the needle will roll like a wheel. This causes the pointer to move.

Readings are taken from a watch and the protractor. Students record both time and degree readings.

A view of the complete apparatus:

Additional info:

To test contraction, students merely remove the heat and continue recording data until the pointer ceases to move.

Click here to go to the student page (lab activity)