Properties of Matter Properties of Matter
Extensive and Intensive Properties Extensive and Intensive Properties
Physical and Chemical PropertiesPhysical and Chemical Properties
Physical change: a change in the physical properties of a substance.
Chemical change: the transformation of one or more substances into others.
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Phases of MatterPhases of Matter
Solid (s) ------ Liquid (l) --------- Gas (g)
Phases: ‘physical state’
Solids
Definite volume and shape
Liquids
Definite volume, but form determined by container it is in
Gases
No definite volume or shape
Solids
Strong attraction between molecules- fixed position (vibrate)
Heat breaks fixed arrangement
Liquids
Molecules ‘flow’
Gases
Heat causes attractions between individual molecules to be broken
Move in random manner
Bump into the container – ‘pressure’
Submicroscopic Level Submicroscopic Level
DiffusionDiffusion
Gas molecules continue to move and bump into each other
Move from higher concentration areas to lower areas of concentration
Occurs in:
Gases, liquids
Diffusion Animation
Phase ChangesPhase Changes
Animation
Process of EvaporationProcess of Evaporation
Molecules are heated below the surface, gain kinetic energy and bump into molecules at the surface
Surface molecules are released (attraction to other molecules broken)
Why is this a cooling process?The slower moving molecules left behind (lower temperature) cools the air or body (perspiration)
CondensationCondensationThis is a warming process
Why?
Gas particles cool and reach the surface. Kinetic energy absorbed by surface molecules. Molecules form attractions
This increases temperature
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