Ihe na-eme ka ikuku oxygen bụ ngwaọrụ na-etinye uche na ikuku oxygen site na ikuku gas (nke na-emekarị ikuku ikuku) site na ịhọrọ nke ọma na-ewepụ nitrogen iji nye ikuku gas ngwaahịa nwere oxygen. anyị Ihe nchekwa oxygen nwere ike ịbụ maka ahụike ma ọ bụ eji ụlọ.