Ozone is produced naturally through photochemical and electric discharge reactions. Photochemical production occurs when high energy radiation from the sun strikes ordinary oxygen molecules in the upper atmosphere. Electric discharges, including lightning and sparks from motors, also convert ordinary oxygen to ozone. Ozone is produced commercially by electric discharges in a machine. Ozone has a molecular weight of 47.998.
Pure ozone is a pale blue gas that has a sharp, irritating odor.
The word ozone comes from a Greek word meaning to smell. The German chemist Christian Friedrich Schonbein discovered ozone in 1840. Ozone in the upper atmosphere. Most ozone is found in the upper atmosphere. This ozone layer in the upper atmosphere shields the earth from 95 to 99 percent of the sun's ultraviolet rays.