Some molecular properties of matter

Diffusion

Diffusion The speed with which molecules move about inside a gas depends on their mass and temperature. Thus, at a given temperature the heavy molecules of carbon dioxide move more slowly than the light molecules of hydrogen. This has an important bearing on the rate at which one gas will diffuse into, or mix with another. Thomas Graham found …

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Three states or phases of matter

Three states or phases of matter Matter commonly exists in either the solid, liquid or gaseous state or phase. In a solid substance the molecules vibrate about their zero resultant force tions, alternately attracting and repelling one another. All true solids have a line structure in which the atoms are arranged in a regular pattern called the (Fig. 13.2 …

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Nature of the force between atoms and molecules

Nature of the force between atoms and molecules Newton’s law of universal gravitation which works so well in calculations of the  force between two pieces of matter whose distance apart is large compared with the size, fails to give the right answer when applied to two molecules. close together. This does not mean that gravitational attraction no …

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Brownian movement. Kinetic theory of matter

Brownian movement. Kinetic theory of matter One day in the year 1827 the botanist, Robert Brown, was using a microscope to examine some pollen particles in water when he was surprised to notice that they were in a continuous state of vigorous haphazard movement. At the time Brown could offer no explanation, but many years afterwards it came …

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Some molecular properties of matter

Some molecular properties of matter Atoms and molecules Many of the ancient Greek philosophers believed that all substances were composed of tiny particles or atoms; but it was not until the nineteenth century that this idea developed into a useful theory for explaining some of the chemical and physical properties of matter. In 1808, the English chemist, John Dalton, …

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