Information AboutMelting Point |
| CATEGORIES ABOUT MELTING POINT | |
| fundamental physics concepts | |
| chemical properties | |
| phase changes | |
| phases of matter | |
| quark matter | |
| exotic matter | |
|
The melting point of a Crystalline Solid is the Temperature range at which it changes State from solid to Liquid . Although the phrase would suggest a specific temperature and is commonly and incorrectly used as such in most textbooks and literature, most crystalline compounds actually melt over a range of a few degrees or less. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the '''freezing point'''. FUNDAMENTALS (°C)]]For most substances, Melting and Freezing points are equal. For example, the melting point ''and'' freezing point of the Element Mercury is 234.32 Kelvin (−38.83 °C or −37.89 °F ). However, certain substances possess differing solid-liquid transition temperatures. For example, Agar melts at 85 °C (185 °F) and solidifies from 31 °C to 40 °C (89.6 °F to 104 °F); this process is known as Hysteresis . Certain materials, such as Glass , may harden without crystallizing; these are called Amorphous Solid s. Amorphous materials as well as some polymers do not have a true melting point as there is no abrupt phase change at any specific temperature. Instead, there is a gradual change in their Viscoelastic properties over a range of temperatures. Such materials are characterized by a Glass Transition Temperature which may be roughly defined as the "knee" point of the material's density vs. temperature graph. |
|
|