heat

• Thermal energy


  The sum of potential and kinetic particles in a material
• temperature 


  measure of average kinetic energy of particles in a material
• absolute zero


  minimum temperature of a substance
• kelvin scale 


  symbol, k
• heat 


  heat is energy transferred between two objects because of a temp diff.

  
  

  symbol, Q

  
  

  Heat flows from a high temp to a low temp (thermal equilibrium)

  
  

  flow of heat into a substance increases its thermal energy and temp
• heat transfer 


  the transfer of heat can occur through different methods.

  convection, conduction and radiation
• conduction


  transfer of heat through collisions between adjacent particles in a material

  low temp --> high temp
• convection 


  heat is transferred through movement of fluid

  high --> low

  heated fluid is expanded and becomes less dense and rises through the fluid. fluid then cools and becomes denser and sinks through the fluid.
• radiation


  process of heat transfer through emission of radiation of objects above absolute zero

  hot --> cold
• Thermal Conductors


  Materials that allow heat to flow easily, such as metals like copper and aluminum.

  
  

  free moving electrons transfer heat rapidly as they collide with atoms in the structure of a metal
• Thermal Insulators


  Materials that resist the flow of heat, such as fiberglass and foam.
• Latent Heat


  The energy required to change the state of a substance (solid, liquid, or gas) without changing its temperature.
• Latent Heat of Fusion


  The energy required to change a substance from solid to liquid or vice versa.
• vapour Vaporization

  the heat that has to be given to a unit mass of material to convert it from the liquid to the vapour phase without a change in temperature.
• Latent Heat of Sublimation

  The energy required to change a substance from solid to gas without going through the liquid phase.
• What is thermal expansion?

  The change in length or volume of a substance as a result of a change in its temperature
• Metals tend to have higher coefficients of linear expansion compared to non-metals because their atoms are held together by metallic bonds which allow them to vibrate freely and expand easily.
• specific heat capacity 


  the specific heat capacity(symbol c) of a substance is the amount of heat that must be added to one unit of mass of the substance in order to cause an increase of one unit in temperature.