easy

• what is solid to liquid called

  melting
• what is liquid to solid called

  freezing
• liquid to gas

  boiling
• gas to liquid 


  condensation
• solid straight to gas

  sublimation
• how do you use melting point data to distinguish between pure substances and mixtures

  pure substances have a sharp exact melting point whereas mixtures melt over a range of temperatures since they consist of several elements/compounds