particle model of matter

• structure of a solid:

  • strong forces of attraction
  • fixed structure
  • vibrate to transfer energy
  • high particle density
• structure of a liquid:

  • weaker forces of attraction
  • irregular structure
  • more energy than solids
  • less dense than solids
• structure of gases:

  • almost no forces of attraction
  • move randomly
  • fill their container
  • highest energy
  • low density
• what is density?

  mass per unit volume- how tightly particles are packed
• density equation:

  density = mass / volume
• calculating the density of irregular objects:

  • use a balance to find the mass
  • fill eureka can with water and place the object in it
  • measure the water displaced from the can
• what is internal energy?

  the total energy that a systems particles have in their kinetic and potential energy
• if you heat the particles there will be an increase in the kinetic energy store, which will overall increase the internal energy. If the internal energy store increases enough there will be a change in state
• what is specific latent heat?

  the energy required to change 1kg of a substance without changing its temperature
• specific latent heat equation:

  energy = mass x specific latent heat
• when a substance gets heated there is an increase in energy, which results in a temperature increase.

  During a change in state, the energy goes into breaking the bonds so temperature increase stops
• what is pressure?

  Force per unit area.