天然气 (tiān rán qì)

Character breakdown

• 天 (tiān) · 4 strokes

  Depicts a person (大) with an emphasized head. Based on the original meaning "head". The meaning later shifted to "top", "high", and "sky".

• 然 (rán) · 12 strokes

  Phonosemantic compound. 灬 represents the meaning and 肰 represents the sound. Based on the original meaning "burn", now written as 燃. The current meaning is a phonetic loan.

• 气 (qì) · 4 strokes

  Depicts a gust of air.