The ozone layer

Ozone is a triatomic molecule, consisting of three oxygen atoms.Ozone in the lower atmosphere is an air pollutant with harmful effects on the respiratory systems of animals and will burn sensitive plants; however, the ozone layer in the upper atmosphere is beneficial, preventing potentially damaging ultraviolet light from reaching the Earth's surface.Ozone is a pale blue gas, slightly soluble in water and much more soluble in inert non-polar solvents such as carbon tetrachloride or fluorocarbons, where it forms a blue solution. At –112 °C, it condenses to form a dark blue liquid. It is dangerous to allow this liquid to warm to its boiling point, because both concentrated gaseous ozone and liquid ozone can detonate. At temperatures below –193 °C, it forms a violet-black solid.

Ozone layer

The highest levels of ozone in the atmosphere are in the stratosphere, in a region also known as the ozone layer. Ozone used in industry is measured in ppm(OSHAexposure limits for example), and percent by mass or weight.This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is damaging to life on Earth.[1] It is mainly located in the lower portion of the stratosphere from approximately 13 to 40 kilometres (8.1 to 25 mi) above Earth, though the thickness varies seasonally and geographically

Ozone was discovered by Christian Friedrich Schönbeinin 1840, who named it after the Greekword for smell (ozein), from the peculiar odor in lightning storms.The odor from a lightning strike is from electrons freed during the rapid chemical changes, not the ozone itself.