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Fusion

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-267

2025-11-24

413

Demonstration. - Draw out a piece of glass tubing until its inner diameter is 1 mm.cr less, and close the end. Drop into the open end a small piece of beeswax and hold the tube in a flame until the wax is melted. Let it solidify at the closed end. Tie the tube to a thermometer as shown in Fig. 1. Put the thermometer and tube into a beaker of water and heat it until the wax melts. Take the temperature of melting, remove the source of heat, and again read the thermometer at the instant that the wax begins to solidify. Take the mean of the two readings as the melting point of the wax.

The change from a solid to a liquid as a result of the application of heat is called fusion, or melting. The temperature at which a solid melts is called its melting point. The laws of fusion are as follows:

1. Every solid having a crystalline structure begins to melt at a certain fixed temperature that is always the same for that substance if the pressure is constant.
2. II. The temperature of a melting solid remains unchanged from the time melting begins until the body is entirely melted.