KINETIC PARTICLE THEORY
Kinetic Particle Theory
Matter - A substance that has mass and occupies space. E.g. :
- Solid
- Liquid
- Gas
- Plasma
- Bose-Einstein condensate
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Kinetic Particle Theory - All matter is made up of tiny particles and these particles are in constant random motion.
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SOLID
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Closely packed in orderly manner
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Strong forces of attraction
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Vibrates about fixed positions
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Cannot move freely
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Fixed volume, not compressible
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LIQUID
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Arranged in disorderly manner
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Weaker forces of attraction than solid
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More kinetic energy than solid
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Not held in fixed positions, move freely through liquid
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Fixed volume, not compressible
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GAS
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Spread far apart from one another
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Weaker forces of attraction than liquid
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Lot of kinetic energy, no fixed position
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Can move rapidly in any direction
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No fixed shape, compressible
Figure 2. Cooling Curve
Figure 1. Solid, Liquid, Gas
Changes in State
Melting - Process by which a substance changes from a solid to a liquid.
Melting point - Temperature at which a solid becomes a liquid.
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Freezing - Process by which a substance changes from a liquid to a solid.
Freezing point - Temperature at which a liquid becomes a solid.
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Boiling - Process by which a substance changes from a liquid to a gas.
Boiling point- Temperature at which the vapor pressure of a liquid becomes equal to the external pressure.
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Evaporation - Process by which a liquid changes to a gas at temperatures lower than the boiling point.
Condensation - Process by which a gas changes into a liquid.
Sublimation - Process by which a solid changes directly into a gas.
Solidification - Process by which a gas changes directly into a solid.
Volatile Liquids - Liquids that evaporate quickly at room temperature
Figure 3. Heating Curve
Figure 4. Changes in State
Diffusion
Graham's Law of Diffusion: Diffusion is inversely proportionate to the square root of density
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Diffusion - The net movement of particles from an area of higher concentration to an area of lower concentration across a concentration gradient.
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Diffusion takes place in ALL substances (very slow in solids, thus ignored)
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Affect of Density and Temperature on Diffusion:
DENSITY: Particles move slower if they are denser, slower diffusion.
TEMPERATURE: Heat increases kinetic energy, faster diffusion.
