1.1 States of Matter

• Three states of matter

  Solids, liquids, gases
• Particle model

  • Explains the properties of substances in their different states
  • Explains changes of state
• Matter


  Sub-atomic particles and anything made from them, such as atoms and molecules
• Energy

  The capacity of a system to do work or the quantity required for mechanical work to take place
• Particle

  A general term for a small piece of matter, e.g. protons, neutrons, electrons, atoms, ions or molecules
• Physical properties

  A description of the appearance of a substance or how it acts without involving chemical reactions
• Solid: shape, flow, compression

  • Have a fixed shape and cannot flow
  • Cannot be compressed
• Liquids:shape, flow, compression

  • Flow and take the shape of their container
  • Cannot be compressed
• Gases: shape, flow, compression

  • Flow and completely fill their container
  • Can be compressed
• A single particle does not have the properties of the material it is part of. The properties of a substance are the properties of a huge number of particles together.
• Solid: closeness, arrangement, movement, energy

  • Particles very close
  • Particles in regular pattern
  • Particles vibrate around fixed position
  • Particles have low energy
• Liquid: closeness, arrangement, movement, energy

  • Particles close
  • Particles randomly arranged
  • Particles move around each other
  • Particles have greater energy
• Gas: closeness, arrangement, movement, energy

  • Particles far apart
  • Particles randomly arranged
  • Particles move quickly in all directions
  • Particles have highest energy
• The particles in the diagrams could be atoms, molecules or ions
• Diffusion


  The movement of particles from an area of high concentration to an area of low concentration until they are evenly distributed
• Solute


  The substance that is dissolved in a solvent to form a solution
• Solvent


  The liquid in which a solute is dissolved to form a solution
• Solution


  A homogeneous mixture formed when a solute is dissolved in a solvent
• Dilution


  The process of reducing the concentration of a substance in a liquid by adding more solvent
• Concentration


  The number of particles of a substance per unit volume of liquid (e.g., per dm³ or liter)
• Solubility


  The mass of solute that can dissolve in 100 cm³ of solvent at a particular temperature
• Saturated Solution


  A solution in which no more solute can dissolve at a given temperature; it contains the maximum amount of dissolved solute
• Unsaturated Solution


  A solution that can still dissolve more solute at a given temperature
• Ammonium Chloride (NH₄Cl)


  A white solid formed by the reaction of ammonia (NH₃) with hydrogen chloride (HCl)
• Diffusion in Gases


  The process where gas particles move from an area of high concentration to an area of low concentration until evenly mixed, as seen in the experiment with bromine gas and air
• Diffusion in Liquids


  The process where liquid particles move from an area of high concentration to an area of low concentration, occurring slower than in gases due to lower particle energy
• Ammonia (NH₃)


  A gas that diffuses quickly due to its lighter molecules, used in diffusion experiments with hydrochloric acid
• Hydrochloric Acid (HCl)


  A gas that diffuses slower than ammonia due to its heavier molecules, used in diffusion experiments with ammonia
• Diffusion Rate Factors

  • Temperature (higher temperatures increase kinetic energy and diffusion rate)
  • Concentration gradient (greater differences in concentration increase diffusion rate)