Most of the UV in the mid-range of energy is blocked by the ozone layer the lower energy part of which is too long for ordinary dioxygen in air to absorb .
The ozone layer absorbs strongly in the important 200 -- 315 nm range .
Most of the UV in the mid-range of energy is blocked by the ozone layer , which absorbs strongly in the important 200 -- 315 nm range , the lower energy part of which is too long for ordinary dioxygen in air to absorb .