instruction: Classify the following elements as metal or noble gas: Argon, Iron, Copper, Krypton, Neon, Silver, Thorium, Radon, Helium, Xenon, Erbium, Tin, Protactinium
response: Argon - Noble Gas
  Iron - Metal
  Copper - Metal
  Krypton - Noble Gas
  Neon - Noble Gas
  Silver - Metal
  Thorium - Metal
  Radon - Noble Gas
  Helium - Noble Gas
  Xenon - Noble Gas
  Erbium - Metal
  Tin - Metal
  Protactinium - Metal