Matter & Molecules

• Sublimation


  Solid to gas phase change without going through liquid phase
• Density

  Mass per unit volume
• Solid to liquid

  Melting
• Liquid to solid

  Freezing
• Liquid to gas

  Vaporisation
• Gas to liquid

  Condensation
• Solid to gas

  Sublimation
• Gas to solid

  Condensation
• When a substance melts, energy is transferred to the particles by heating and the particles gain thermal energy, so they can move around each other as a liquid
• On a cold day, droplets of water form on the inside of a window

  Energy is transferred from the water particles in the air to the colder glass, and water changes from the gas state to the liquid state
• Internal energy

  The energy stored in the particles of a system
• Internal energy increasing in a liquid

  Liquid temperature increases, changes to gas
• Gas has the most internal energy in terms of equal mass
• Particles in a gas when temperature rises

  Gain kinetic energy and move faster
• If a substance melts or boils

  Potential energy of its particles decreases
• Pressure of gas


  Caused by the random impacts of gas molecules on surfaces that are in contact with the gas
• Temperature of gas increased

  Molecules move faster
• Latent heat

  The energy needed for a substance to change state without changing its temperature
• Specific latent heat


  Energy needed to melt (or boil) 1kg of a substance without changing its temperature
• Specific latent heat of ice can be measured using a low voltage heater
• Unpredictable motion of smoke particles in Air as evidence of the random motion of gas molecules.
• In terms of subatomic particles 


  Name amount of Protons, Neutrons and Electrons
• Pressure Cooker

  1.Steam increases so number particles increase to.

  2. As the temperature increases, particles move faster.

  3. Particles collide with the wall of cooker.

  4. Frequent collisions in each collision exerts a force.
• If steam takes up greater volume

  Density = mass divided by volume to the density increases
• If light is not working due to one direction diode

  Reverse the connections of the LED/battery
• Alpha, beta and gamma can all be in same source.
• The longer the half life the more stable the nuclei