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 layer. Ozone-oxygen cycle in the ozone layer. The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.