Learners observe that the melting of a solid and the freezing of its liquid occur at the same temperature. The melting point is an intrinsic property and is used to identify a substance.

In this animated object, learners examine the parts of a plastics extruder. A quiz completes the activity.

Learners examine how melting, vaporization, and sublimation require energy input while freezing and condensation release energy.

In this colorful, interactive object, learners examine how materials on the nanoscale compare with those on the macroscale. The focus is on the difference between macroscale and nanoscale gold in both color and melting point.

In this animated activity, students view the plastic pellets in a profile extrusion machine being melted as the temperature of the heating elements is elevated by a time proportioning control system.

Students view a video that shows the correct methods for starting a GTAW weld pool and adding filler. It focuses on the two problems that many students have – adding filler too soon and angling the torch so that the filler melts prematurely on the filler rod. Note: This activity is 3.6 mb.