C1: The Particulate Nature of Matter

Properties and Structure of different states

Properties Solids Liquids; Gases
Particle Movement Can only vibrate in place, cannot freely move Vibrate, rotate, and translate past each other Vibrate, rotate, and translate freely, colliding with each other
Forces in between particles Strong, particles are closely packed Less than a solid There is no force between particles
Shape and Volume Fixed shape, fixed volume Changing shape, fixed volume Changing shape, changing volume
Arrangement Particles closely packed in a regular pattern Irregular arrangement, particles close Irregular arrangement, particles far apart


Changes in State
  • Melting: The transition of a solid turning into a liquid (by heat energy). Every solid has a melting point at certain temperatures. Melting happens when particles gain energy, causing particle bonds to loosen
  • Boiling: The rapid vaporisation of a liquid into a gas. This happens when the boiling point of a liquid (a certain temperature that is able to break intermolecular bonds) is reached and enough energy breaks up intermolecular bonds
  • Evaporation: The process of a liquid turning into gas/vapour. This happens when particles gain energy and move around more, causing particle bonds to loosen, thus turning a liquid into a gas
  • Freezing: The process of a liquid turning into a solid. This happens when particles lose energy and move around less, causing them to arrange themselves into closely packed fixed positions, thus changing the liquid into a solid
  • Sublimation: The change of a solid turning into a gas without passing through liquid form. This happens when particles gain enough energy to completely destroy the forces between the particles


Some more definitions
  • Atoms: Tiny neutral particles that build up matter
  • Molecules: Two or more bonded atoms
  • Ion: An atom with a charge (negative or positive)


Diffusion
  • Diffusion is defined as the random movement of particles (eg. atoms, ions, molecules) from a region of higher concentration to a region of lower concentration
  • No deliberate action or energy is required for this process to happen
  • Particles with greater molecular mass diffuse slower
  • This is because heavier particles move slower, and will therefore slow the rate of diffusion


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