Density, Internal Energy and States

• What is the formula for density?

  Density = mass / volume
• What does internal energy refer to in a system?

  Total energy stored by the particles
• What are the two forms of energy included in internal energy?

  Kinetic and potential energy
• What happens to the internal energy of a system when it is heated?

  It increases the internal energy
• What are the two possible outcomes of heating a system?

  Increase temperature or change state
• What are the changes of state in matter?

  • Freeze: liquid to solid
  • Melt: solid to liquid
  • Sublimate: solid to gas
  • Boil or evaporate: liquid to gas
  • Condense: gas to liquid
• What is true about mass during changes of state?

  Mass is always conserved
• What is the state of matter when it freezes?

  Solid
• What is the state of matter when it melts?

  Liquid
• What is the state of matter when it sublimates?

  Gas
• What is the state of matter when it boils or evaporates?

  Gas
• What is the state of matter when it condenses?

  Liquid