Chemical Properties-

• Noble gases are extremely unreactive compared to other elements
• Noble gases are inert
• When elements react, their atoms complete their outer shells by losing, gaining, or sharing electrons
• Noble gases have complete outer shells, so they do not tend to lose, gain, or share electrons, making them inert and unreactive
• Group 1 and 7 elements have incomplete outer shells, making them reactive
• Group 0 elements have complete outer shells, making them unreactive
• Properties of noble gases:

  • Low densities
  • Inert, so they are not flammable
• Uses of noble gases are linked to their low densities and inert properties
• Helium:

  • Used as a lifting gas in party balloons and airships
  • Less dense than air, so balloons and airships rise
  • Non-flammable, so helium cannot set on fire
• Argon:

  • Used as a 'shield gas' in welding
  • Denser than air, so it prevents air from reaching the metal
  • Inert, so it prevents hot metal from oxidizing and spoiling the weld