Purpose:To illustrate room temperature paramagnetism
Description:Pendula of different materials are suspended here from a horizontal rod. As a large magnet is moved in next to them, we see an unsurprising response. The steel pendulum leaps over to the magnet; the wooden pendulum is entirely unaffected. There is a third pendulum, however, that appears to be slightly, but not very strongly, attracted to the magnet. The bob on this pendulum is a lump of dysprosium.
This demonstration can be valuable used in conjunction with J7-14: Curie Point of Dysprosium, to show the change in dysprosium's behaviour at different temperatures. Encourage students to visualize the magnetic dipoles within the material and how they may change at this transition.