Related Clues:

• None can alter this element
• It's a gas!
• Glass tube filler
• Advertising element
• Arc lamp gas
• Cryogenic refrigerant
• Gas for the theater district
• Noble gas
• Incandescent lamp gas
• Las Vegas lights
• Extra-bright
• Light stuff
• Broadway brightener
• Glaring lure on the strip
• Gas that's hard to ignore