Structure and Properties of Matter

This introductory chapter starts with a differentiation between the states of matter, wherein the common ones are solids which are fixed in volume and shape, liquids that have no predetermined shape, and gases that have no predetermined shape nor volume. Glass and plasma are also noted, as the rather uncommon states but they are frequently present in certain metallurgical processes. The states are discussed based upon intermolecular/ionic relationships which give rise to the variety of observed properties. A discussion is given to the commonly encountered fluids with regard to why and how they differ from the solid and gaseous states. The pertinent thermodynamic properties of melting point, boiling point, and critical temperature are introduced. The glass transition is also included.A knowledge of the atomic scale structure of fluids such as metallic liquids and oxide melts, which are closely related to various metallurgical processes, is essential to the understanding of their characteristic properties. The in situ measurement on fluids by techniques such as X-ray diffraction has provided successfully direct fundamental information of the structure of metallurgical melts. Thus, this chapter also provides an essential procedure for determining the structure of fluids using X-rays with some selected structural features of metallic and oxide melts.