Princeton's WordNet (3.00 / 1 vote) Rate this definition: opacity (noun) the phenomenon of not permitting the passage of electromagnetic radiation. opacity, opaqueness (noun) incomprehensibility resulting from obscurity of meaning. opacity, opaqueness (noun) the quality of being opaque to a degree; the degree to which something reduces the passage of light
Ozone is a gas that is naturally present in our atmosphere. It was first identified in laboratory experiments in 1839 and has the chemical formula O3 because an ozone molecule has three oxygen atoms attached to it.zone is a gas that is naturally present in our atmosphere. It was first identified in laboratory experiments in 1839 and has the chemical formula O3 because an ozone molecule has three oxygen atoms attached to it.
Ozone (O 3) is a constituent of the troposphere (it is also an important constituent of some regions of the stratosphere commonly known as the ozone layer). The troposphere extends from the Earth 's surface to between 12 and 20 kilometers above sea level and consists of many layers.zone is more concentrated above the mixing layer, or ground layer. Ground-level ozone, though less concentrated than ozone aloft, is more of a problem because of its health effects. Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night.