Possible Clues:

• Most prevalent gas in air
• Gas Newton compressed expanded again
• Inert nog is an inert gas
• Gas forming about four-fifths of atmosphere
• It comprises about four-fifths of the atmosphere
• It forms the greater part of air
• It would be great gas to go and intern this
• This will give you N, or get 27 across
• Most of our air needs re-toning
• 78% of atmosphere