Kinetic Theory of Matter - Essay Example

Kinetic Theory of Matter (Heat and Temperature) of KINETIC THEORY OF MATTER Kinetic theory – this particular theory says that all three states of matter (gases, liquids and solids) possess some energy resulting from the constant motions of the atoms and molecules that comprise matter. This energy from motion is called as kinetic energy. This particular energy can be measured through the temperature of that matter (whether it is in gas, liquid or solid form) or stated differently, the hotness or coldness of matter can known by measuring its temperature.

This means that more kinetic energy in matter makes it hotter, or conversely, less kinetic energy makes the matter colder. There are some characteristics of kinetic energy; among these is a rule that heat transfers occur from the hotter body of matter to the colder matter and not the other way around, unless energy is expended against the natural process (from hot to cold). Relationship of heat to kinetic theory – the importance of this relationship is that kinetic energy in the form of heat can be utilized to operate machines and perform some kind of work.

A close understanding of the kinetic theory of matter led to the formulation of the three laws of the theory of thermodynamics today, which are the following: the first law states that energy cannot be created or destroyed but merely converted from one form to another form (an example will be heat energy converted to electrical energy) and in a closed system, energy is always conserved; a second law states that a closed system has entropy or a state of disorder, and the tendency is to be moving towards a state of order or equilibrium (or into a state of inert uniformity) and the second law is sometimes called as the law of entropy; the third law states that the entropy of any system is to approach a constant value as the temperature approaches to zero.

A fourth law, which was a newly-formulated one in modern physics, states that if two systems are in thermal equilibrium as regards a third system, it is assumed they are all in thermal equilibrium with each other. The kinetic theory of matter and the laws of thermodynamics has important implications because it allows for work to be performed through various practical applications. Further to this, the theory makes it understandable the inter-relationships between work, heat, pressure, energy, pressure and volume (applicable to the gaseous state of matter) and the use of these principles.

A good application of this theory in practical terms is that heat is not some form of substance but it is rather a form of energy (kinetic energy derived from the motion of atoms and molecules) and as such, can be converted to mechanical energy (Cassidy, Holton & Rutherford, 2002, p., 293). What is heat – it is actual energy as measured in joules or some other form of measure, such as in energy units. In short, heat is the amount of energy in a substance. If one adds energy to a substance, it becomes hotter as a result of that action.

Conversely, if you add heat to it, then the substance acquires more energy in the form of kinetic energy of the atoms and molecules. In other words, heat as energy can be used to break the bonds between molecules, as in the case of heat used to melt ice (solid) into a liquid but kinetic energy has not been increased in this case. If heat as energy is added to a substance, two things can happen which are the matter will change in its state (as cited earlier, from solid ice to liquid water without an increase in its temperature, or there is a rise in temperature, such as when water is heated so that it reaches the boiling point).

What is temperature – it is merely a number used to measure the amount of heat or the energy present in a substance. Put another way, temperature is not a form of energy, which may be a bit confusing to some people. Temperature is related to energy in some other way, in that it is used to measure the amount of energy in the form of kinetic energy of a substance. It is a good and reliable way to measure the kinetic energy of the atoms and molecules in a substance. Relationship of heat and temperature – the various scales used in temperature readings (such Celsius, Fahrenheit or Kelvin) is the way by which heat (or kinetic energy) in a substance can be reliably and predictably measured.

So when heat (as a form of energy) is applied to matter then its temperature will inevitably rise (except when the matter changes in form). The added or new energy applied to a substance then increases its kinetic energy which is manifested by a rise in the temperature of that particular substance. The difference is that heat is kinetic energy while temperature is merely a way to measure the energy present in a substance. Various properties – different substances have different heat capacities.

In this instance, heat capacity is defined as the amount of heat required to raise the temperature of a substance by one degree Celsius. Since the heat capacity of a substance varies with its volume, scientists use a more precise measurement which is the specific heat, or the amount of heat to raise temperature of a gram of substance (the gram being a common denominator) by one degree Celsius. This is to make different substances comparable by some measure (1 gram, 1 degree Celsius) but there are other properties which determine the heat capacity of a substance.

These are pressure, a chemical composition of the substance itself and the energy state of the substance (or its temperature). As an example, water has a specific heat of 4.18 joules per gram per degree Celsius, or if measured in calories, it requires 1 calorie per gram per degree Celsius (Ebbing & Gammon, 2010, p. 237). Various sources of heat – it can come from a variety of sources, such as friction, light, chemical reactions, radio-magnetic radiation, sound waves, electricity, nuclear reactions such as fusion or fission and even matter itself (as evidenced by Einstein's famous equation).

Heat can be derived from food by digestion or from the burning of certain fuels (Kothandaraman, 2008, p. 1). Reference List Cassidy, D. C., Holton, G. J. & Rutherford, F. J. (2002). Understanding physics. New York, NY, USA: Springer-Verlag. Ebbing, D. & Gammon, S. D. (2010). General chemistry. Florence, KY, USA: Cengage Learning. Kothandaraman, C. P. (2008). Fundamentals of heat and mass transfer. New Delhi, India: New Age International Publishers.