changes in matter
DESCRIPTION
Changes in Matter. ISCI 2002 Chapter 11. Phases 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 . - PowerPoint PPT PresentationTRANSCRIPT
• 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’
• 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
• 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)
• This is a warming process
• Why?
• Gas particles cool and reach the surface. Kinetic energy absorbed by surface molecules. Molecules form attractions– This increases temperature
• 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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