]> 2 2 3 4 5 6 7 8 10 12 2 4 2 3 4 2 3 2 3 4 6 8 10 12 16 2 2 3 A nearly colorless gas, it is a very strong absorber of ultraviolet radiation, and the presence of the ozone layer in the upper atmosphere provides an ozone shield that prevents dangerous radiation from reaching the earth's surface. 4 5