Physical transformations of matter

Chapter 4 discusses chemical and physical transformations of matter, both those that occur naturally in the environment and in living organisms and those that are invented by chemical scientists. The study of transformations spans the range from efforts to gain a fundamental understanding of naturally occurring... 

A principal goal of the chemical sciences is to understand and manipulate chemical and physical transformations of matter. We are using the term transfor-... 

For a complete mass balance over a balance area at steady-state, in which only physical transformation of matter occurs, an equilibrium system consisting of Eq. (1-3) and k - 1 equations (1-4) for k active components over the balance area, must be set up. Due to the valid stoichiometric condition, for the individual phases, the A equation (1-4) gives... 

THE CHEMICAL AND PHYSICAL TRANSFORMATION OF DETRITAL PARTICULATE ORGANIC MATTER... 

Many of the unsolved problems of physics and chemistry were concerned with combustion and detonation. A really well-developed scheme of normal combustion is seldom realized in nature. The most common form of gaseous combustion - turbulent combustion - was found to be the result of the hydrodynamic instability of the combustion process in a flow. Even in the simplest system, the physical scheme of turbulent combustion is very far from being perfectly understood. Just as in the analysis of detonative combustion, it is still possible to speak only of the universal instability of the hydrodynamic process accompanying the chemical transformation of matter. Actually, "turbulence is hardly the term for the result of the manifestation of this instability - the appearance of a multifront shockwave in the detonation front. However, the derivation of a complete physical scheme of detonation (especially in relation to condensed expls) will eventually follow from further research in this field... 

The combustion is an extremely complex process including many chemical and physical phenomena of transformation of matter. The need and desire to know and control this process urges man to study its various aspects. Organic polymers are but one example of the multitude of materials used by man. They possess peculiar features and properties which individually affect the material behavior in a critical fire situation. It is, therefore, important to study the flammability characteristics of polymeric materials and the factors affecting them. 

The fundamental premise of chemistry is that all matter consists of molecules. The physical and chemical properties of matter are those of the constituent molecules, and the transformation of matter into different materials (compounds) is the result of their reactions to form new molecules. A molecule consists of two or more atoms held in a relatively fixed array via valence-electron orbital overlap (covalent bonds chemical bonds). 

In the last three decades, nuclear magnetic resonance has become a powerful tool for investigating the structural and physical properties of matter. Today, nuclear magnetic resonance is the physical method most widely used in analytical chemistry. For special applications, e.g. relaxation time measurements, there is available a variety of modifications of the basic nuclear magnetic resonance experiments such as pulse and spin-echo methods. In the course of this development and when electronic computers were provided at a reasonable price, Fourier transform spectroscopy was applied to nuclear magnetic resonance in the middle of the sixties. At that time, Fourier methods were already used to a large extent in far infrared spectroscopy (see Refs. and references cited therein). 

Pieces of coal are mixtures of materials somewhat randomly distributed in differing amounts. The mineral matter can be readily distinguished from the organic, which is itself a mixture. Coal properties reflect the individual constituents and the relative proportions. By analogy to geologic formations, the macerals are the constituents that correspond to minerals that make up individual rocks. For coals, macerals, which tend to be consistent in their properties, represent particular classes of plant parts that have been transformed into coal (40). Most detailed chemical and physical studies of coal have been made on macerals or samples rich in a particular maceral, because maceral separation is time consuming. 

Chemistry is the science of the combination of atoms, and physics is the science of the forces between atoms. Simply stated, chemistry deals with matter and its transformations, and physics deals witli energy and its transformations. These transformations may be temporaiy, such as a change in phase, or seemingly penmnent, such as a change in the form of matter resulting from a chemical reaction. The study of atomic and molecular structure deals witli tliese transformations, and can be used to make a preliminary identification of a healtli liazard. 

---