Molecular Motion In Matter
The molecules of matter it is in a solid state are believed to vibrate or oscillate around fixed positions or locations. Individual molecules have a unique tendency to cling together by a force called cohesion. This forces does not permit molecules to move very far away from their original position. As a result of this condition, solid have a tendency to take on a definite shape.In liquids, molecule are not held together firmly in a rigid pattern. The cohesion force between individual molecules, however still exist. The resulting space between molecules is somewhat greater than that of a solid material. This unique difference in a liquid causes individual molecules to have more freedom in their movement. They have a greater tendency to slip over each other and to
move a round with ease. As a result of this condition, molecules in a liquid do not remain in fixed positions, which causes the material to be in a constant state of change liquids do not have specific shape but, rather conform to the dimensions of container into which they are placed.
In gases individual molecules are spread apart a great deal more than their liquid and solid state counterparts. This is exemplified by the fact that one cubic foot of water will expand into 1600 cubic feet of steam when it changes state. Gas molecules exert practically no cohesive force upon one another. This lack of attracting force and their high moving velocity explains why gases are void of shape and volume.