P3 - Particle Model of Matter

• Density in terms of Particle arrangement

  The amount of atoms in a given space and how closely packed together they are.
• Density Equation

  Density = Mass/Volume

  D (g/cm3)=M(g)/V(cm3)
• Particle Arrangement in Solids

  Very close together

  Can't be compressed or squashed (usually)

  Forces of attraction hold them together and in place

  Arranged in a regular way

  Vibrate around a fixed position

  Low energy

  Can't flow

  Hotter the solid gets, the faster the particles vibrate -> Expansion
• Particle Arrangement in Liquids

  • Arranged randomly
  • Very close together, touching many of their neighbours
  • Some gaps, but can't usually be compressed/squashed
  • Enough energy to break free of some of the forces of attraction
  • Can move around and over each other
  • Can flow/be poured
• Particle Arrangement in gasses

  • Widely spaced
  • Randomly arranged
  • Easily compressed or squashed
  • Enough energy to overcome the forces of attraction
  • Free to move in any directions
  • Collide with each other as move in straight lines -> More energy
• What happens to particles during a change of state?

  The number of particles does not change during a change of state, only their spacing and arrangement. As a result, the total mass has not changed.
• Energy Equation

  Energy=Mass x Specific Latent Heat

  E=m * L
• Difference between specific Latent Heat and specific heat capacity

  The energy required for a particular change in temperature is given by the specific heat capacity.

  The energy required for a particular change in state is given by the specific latent heat.
• Explain Internal Energy

  Internal energy of a system or a body with well defined boundaries is the total of the kinetic energy due to the motion of molecules and the potential energy associated with the vibrational motion and electric energy of atoms within molecules. Internal energy also includes the energy in all the chemical bonds.
• Density Required Practical (Irregular solids)

  Measure the mass of the object using scales.

  Fill a Eureka can till it's just starting to overflow.

  Place a measuring cylinder under the spout of the Eureka can and place in the irregular solid, submerging it under the water. The displacement of water equals the volume.

  Use the equation density = mass / volume to find the density and record your results.
• Energy= Mass x Specific Latent heat