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 Eileen Chia(9) This is a Physics blog 3B2 Tagboard Links and Credits linkone linktwo Layout: hearteditorials Codes: -ambulance Icon: biconcave |
Wednesday, September 3, 2008
Chapter 7: Kinetic Model of Matter
Matter is commonly defined as the substance of which physical objects are composed, not counting the contribution of various energies or force fields, which are not usually considered to be matter per se (though they may contribute to the mass of objects). Matter constitutes much of the observable universe, although again, light is not ordinarily considered matter. Unfortunately, for scientific purposes, "matter" is somewhat loosely defined. It is normally defined as anything that has mass and takes up space. Matter (energy) can be in several different states, the most common being high energy physics, solids, liquids and gases. Anything which both occupies space and has mass is known as matter. In physics, there is no broad consensus as to an exact definition of matter, partly because the notion of "taking up space" must be ill-defined for quantum reasons. Physicists generally do not use the saying when precision is needed, preferring instead to speak of the more clearly defined concepts of mass, energy and particles.  SOLID Arrangement of particles: - Closely packed together, usually in a regular pattern, occupying minimum space - Results in solids having high densities Movement of particles: - Vibrate about fixed positions only. Held in position by very strong intermolecular bonds - Explains why solids have fixed volumes and shapes LIQUID Arrangement of particles: - Randomly arranged with the particles slightly further apart as compared to that of solids - Results in liquids having relatively high densities Movement of particles: - Free to move about but confined within the vessel containing it. Have attractive forces between particles - Explains why liquids have fixed volumes but will take the shape of vessels containing them GAS Arrangement of particles: - Very far apart. Particles are randomly arranged and will occupy any available space - Results in gases having low densities Movement of particles: - Particles have very little attraction between them and move about randomly at very high speeds - Explains why gases have no fixed volume and shape, and why they are highly compressible *There are more than 3 states of matter, but most people only know the gaseous, liquid and sold states. One other well-known state of matter is plasma, found in plasma televisions or plasma spheres. BROWNIAN MOTION  Brownian motion: - Random or irregular motion of smoke particles in air - Occurs only in fluids Effects of Temperature on molecular motion - The higher the temperature, the more vigorous and agitated the motion of smoke particles get - The lower the temperature, the less vigorous and agitated the motion of smoke particles will be Why is this so? Air molecules are bombarding the smoke particles more vigorously and frequently. This means that air molecules have greater speeds at higher temperatures. When the temperature increases, a larger amount of thermal energy is converted to kinetic energy of the air molecules. This will cause the molecules to move faster. END OF CHAPTER SEVEN :D |