ˈkēmə, ¦keməˌˌ noun
Etymology: chem- + sphere
: a stratum of the upper atmosphere in which photochemical reactions are prevalent and which begins about 20 miles above the earth's surface
ˈkēmə, ¦keməˌˌ noun
Etymology: chem- + sphere
: a stratum of the upper atmosphere in which photochemical reactions are prevalent and which begins about 20 miles above the earth's surface
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012