Particle model of matter

• Density is measured in kilograms per metre cubed
• Volume of a sphere = 4/3 x pi x r^3
• Volume of a cone = 1/3 x height x r^2 x pi
• Describe an experiment to find the density of an irregularly shaped object


  • Measure mass of object using top pan balance
  • Fill a displacement can, so the water is level with the bottom of the pipe
  • Drop irregularly shaped object into water carefully
  • Wait until water stops leaving displacement can
  • Measure volume of displaced water in the cylinder
  • Use the equation for density to calculate density of object
• Vernier callipers are used to measure small measurements with accuracy
• Potential errors when finding an object's density

  • Different calibrations of top pan balances
  • Different measuring cylinders have different resolutions
  • Incorrect set up of displacement can
• Sublimation is a solid to a gas.
• The internal energy is the total energy of the particles in a system, including the kinetic and potential energies.
• Horizontal regions on heating and cooling graphs mean a change in state