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SYMMETRY OF MATTER |
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SYMMETRY OF MATTER |
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Changing states of matter is about changing densities, pressures, temperatures, and other physical properties. The basic chemical structure does not change. Water is a good example of how atmospheric changes continuously change water into different phases of matter. When water is heated, it changes from liquid to gas (water vapor.) This process is called evaporation. When water vapor is cooled, as it would be if it were taken higher in the atmosphere, this gas will condense, or change back to liquid form. Water turns into a solid when it is frozen into ice. |
The specific properties are of great
value in the identification of a substance, for they can be measured
objectively with scientific instruments, and they remain constant for a pure
substance under fixed conditions of temperature and pressure. For example,
the atomic mass 28.0855, is the mass of silicon at rest. This is figure is
obtained from a mass spectrometry which is an analytical technique to measure
very small masses.