test 2

• Particles in solids


  Strong forces
• Arrangement of particles in solids

  Regular
• Spacing of particles in solids

  Tightly packed
• Motion of particles in solids

  Vibrate about a fixed point
• Draw the particles diagrams for solids, liquids and gases
• Temperature


  Related to the average kinetic energy of particles in a system
• Density equation


  ρ = m/V, where ρ = density (kg/m3), m = mass (kg), V = volume (m3)
• Units for density


  kg/m3 or g/cm3
• Definition of density


  The mass per unit volume or the compactness of a substance
• How to find the density of a regular object
• How to find the density of an irregular object
• How to find the density of a liquid
• Normally highest density state

  Solid, except in the case of water
• Internal energy of particles in a system

  The total energy that its particles have in its kinetic and potential energy stores
• Potential energy of particles in a system

  Energy stored between particles (due to the bonds)
• Kinetic energy of particles in a system

  Energy stored in the particles due to their vibration and/or movement
• What happens to particles in a solid when heated

  They gain kinetic energy and start to vibrate more
• Mass is conserved during a change of state
• Changes of state


  Melting, Evaporating/boiling, Condensation, Freezing, Sublimation
• A change of state is a physical change
• Difference between evaporation and boiling

  Evaporation occurs below the boiling point and only at the surface, without requiring an input energy. Boiling occurs at the boiling point throughout the liquid, and requires an input energy.
• Draw a labelled heating curve to show how the temperature of water changes with time as it is heated from solid – liquid – gas
• Specific latent heat of vaporisation

  The amount of energy required to change the state of 1kg of a substance from liquid to gas
• Specific latent heat of fusion

  The amount of energy required to change the state of 1kg of a substance from solid to liquid
• Units for specific latent heat

  J/kg
• Units for specific heat capacity

  J/kg°C
• Relationship between volume and pressure of a gas in a container

  Pressure and volume are inversely proportional (for a gas of fixed mass and a constant temperature)
• Sketch a graph to show the relationship between volume and pressure for a gas in a container
• What causes atmospheric pressure


  It is caused by the particles in the air around us colliding with a surface
• Work done


  The energy transferred from one store to another