Document page
igcse physics notesprinted 71 · PDF 71
124 pagesrevision 46936
printed 71 · PDF 71
Page image rendered from the stored file at 110 dpi; it sharpens as you zoom. Outlines are placed from each region’s stored position on the page (612 × 792 pt).
readable
Source of this text: embedded text layer. The better of the embedded text and OCR is kept.
71
UNIT 2.1
Kinetic particle model of matter
The three states of matter ,solids , liquids and gasses have different properties and
behave in different ways
Solids have a definite shape and volume and the particles can only vibrate about their
fixed space
Liquids have a definite volume but no definite shape . the particles can slide past one
another
Gasses have neither definite volumes nor definite shapes , the particles are spaced far
apart and can move around freely with minimal intermolecular forces
In a change of state of matter ,only the average kinetic energy of the particles changes ,
not the amount or mass of particles
The following are the state changes :
Solid to liquid : Melting
Liquid to Solid : Freezing
Liquid to Gas : Evaporation / Boiling
Gas to liquid : Condensation
Solid to Gas : Sublimation
Arrangement of particles
Solids:
Particles are packed closely in a fixed, regular pattern,
Particles can only vibrate about their fixed positions due to strong intermolecular forces.
Density is high because particles occupy a small, fixed space.
Liquids :
Particles are close but arranged randomly, allowing them to slide past one another.
This fluidity allows liquids to change shape based on their container but maintains a
fixed volume.