Particle Model of Matter Notes

Particle Model of Matter

Key concepts and definitions for quick review.

Particle Model of Matter

  • Matter occupies space and has mass.
  • Composed of tiny particles (atoms/molecules).
  • Particles attract each other.
  • Empty space exists between particles.
  • Particles are in constant motion, moving faster with more energy.

States of Matter

  • Solid: Fixed shape, particles closely packed, vibrate in place, strong inter-particle forces.
  • Liquid: Particles close but move freely, moderate inter-particle forces.
  • Gas: Particles far apart, move freely, very weak inter-particle forces.

Density Comparison

  • Solids: High density, small spaces between particles.
  • Liquids: Medium density, medium spaces.
  • Gases: Low density, large spaces.

Diffusion

  • Spontaneous mixing of substances from high to low concentration.

Brownian Motion

  • Random movement of particles in liquids/gases due to collisions.

Phase Changes

  • Melting: Solid to liquid.
  • Freezing: Liquid to solid.
  • Evaporation: Liquid to gas.
  • Condensation: Gas to liquid.
  • Sublimation: Solid directly to gas.
  • Deposition: Gas directly to solid.
  • Phase changes involve energy and temperature changes.
  • Melting point: Temperature at which solid becomes liquid.
  • Boiling point: Temperature at which liquid becomes gas.
  • Freezing point: Temperature at which liquid becomes solid.

Pressure in Gases

  • Gas particles are in constant, random motion.
  • Kinetic Molecular Theory: Gas properties explained by particle motion.
  • Gas pressure results from collisions of particles with container walls.

Factors Affecting Gas Pressure

  1. Number of molecules: More molecules, greater pressure.
  2. Volume of container: Smaller volume, greater pressure.
  3. Temperature: Higher temperature, greater pressure.

Pressure in Solids

  • Pressure increases with force, decreases with area: P = /A

Pressure in Liquids

  • Increases with depth and density.

Pressure Calculation

  • P = /A where P is pressure (Pascals), F is force (Newtons), A is area (m^2).
  • Pressure is directly proportional to force and inversely proportional to area.

Conversions

  • Mass: grams (g), kilograms (kg), milligrams (mg)
  • Length: meters (m), decimeters (dm), centimeters (cm), millimeters (mm), kilometers (km)
  • Volume: cubic meters (m³), cubic decimeters (dm³), cubic centimeters (cm³), cubic millimeters (mm³)

Volume

  • Volume of regular solid = area of base x height
  • Volume of irregular solid: water displacement method.
  • Units for liquid: cm^3, mL, L, dm^3, m^3

Density

  • \rho = m/V where \rho is density, m is mass, V is volume.
  • Density: mass per unit volume.

Applications of Density

  • Testing for anaemia (low blood density).
  • Determining car battery charge (acid density).