qì

Vapor, is the radical, No. 84, meaning
curling vapors rising from the ground and forming clouds. Ancient forms show the sun 日 and 火 fire which cause the vapors

Compounds
气氛 qìfēn – atmosphere; ambience
气功 qìgōng – qigong
气候 qìhòu – climate
气球 qìqiú – balloon
气压 qìyā – air pressure

Learn more about 气 at Wikionary