Internal energy

• What is internal energy ?

  The total energy stored in a system by the particles
• what is internal energy made up of?

  Kinetic and potential energy of molecules.
• What increases when you heat a solid?

  The internal energy
• What decreases when we freeze a liquid?

  The internal energy decreases
• What is sublimation?

  When a solid turns directly into a gas
• What is an example of sublimation ?

  Carbon dioxide turning solid in room temperature and pressure
• What happens to mass when a state change take place ?

  Conserved
• What is state change ?

  A chemical change
• What happens to the material if we reverse the state change ?

  It recovers its original properties.
• What is evaporation?

  when liquid turns to a gas on the surface of a liquid
• Why dont every particles in the liquid evaporate ?

  Only the ones on the surface of the liquid have enough energy to turn into a gas