Ingenhousz's Heat Conductors

We use a metal box holding rods of different materials to test their ability to conduct heat. The box is filled with boiling water and a paperclip is attached to the end of each rod using petroleum jelly. As the heat moves through the rods, the jelly melts and the paperclips fall off. The different amounts of time taken for each paperclip to fall show which materials are better conductors. The materials used are copper, aluminium, steel, glass and plastic. Physics - Energy And Radioactivity - Learning Points. Metals are better heat conductors than plastics. Metals have different conductivities. Conductivity is linked to the presence of free electrons. A Twig Experiment Film. Let students experience real experiments in lab conditions anywhere, from setup, method all the way through to analysis and real-world application.