ozone

[ oh-zohn, oh-zohn ]

noun

1. a form of oxygen, O 3 , with a peculiar odor suggesting that of weak chlorine, produced when an electric spark or ultraviolet light is passed through air or oxygen. It is found in the atmosphere in minute quantities, especially after a thunderstorm, is a powerful oxidizing agent, and is thus biologically corrosive. In the upper atmosphere, it absorbs ultraviolet rays, thereby preventing them from reaching the surface of the earth. It is used for bleaching, sterilizing water, etc.

ozone

/ ˈəʊzəʊn; əʊˈzɒnɪk; əʊˈzəʊn /

noun

1. a colourless gas with a chlorine-like odour, formed by an electric discharge in oxygen: a strong oxidizing agent, used in bleaching, sterilizing water, purifying air, etc. Formula: O 3 ; density: 2.14 kg/m³; melting pt: –192°C; boiling pt: –110.51°C Technical nametrioxygen
2. informal.
   clean bracing air, as found at the seaside

ozone

/ ō′zōn′ /

1. An unstable, poisonous allotrope of oxygen having the chemical formula O 3 . Ozone forms in the atmosphere through the process of photolysis, when ultraviolet radiation from the Sun strikes oxygen molecules (O 2 ), causing them to split apart. When freed oxygen atoms bump into and join other O 2 molecules, they form ozone. Although ozone is broken down naturally in the atmosphere through chemical reactions with other atmospheric gases (such as nitrogen, hydrogen, and chlorine), in an unpolluted atmosphere the formation and breakdown of ozone is generally balanced, and the total concentration of ozone is relatively constant. The formation and destruction rates of ozone vary with altitude in the atmosphere, and with latitude. Most ozone forms in the 15 to 30 km (10 to 19 mi) altitude range and in latitudes closest to the equator where sunshine strikes the Earth the most. The ozone is then transported northward and southward by wind and is generally most concentrated in areas above the Canadian Arctic and Siberia and above Antarctica. Ozone is used commercially in water purification, in air conditioning, and as a bleach.

Derived Forms

• ozonic, adjective

Other Words From

• o·zon·ic [oh-, zon, -ik, oh-, zoh, -nik], adjective

Word History and Origins

Origin of ozone¹

< German Ozon < Greek ózōn, present participle of ózein to smell; ozo-

Word History and Origins

Origin of ozone¹

C19: from German Ozon, from Greek: smell

A Closer Look

Ozone is both beneficial for and threatening to all of Earth's organisms, including human beings, depending on how high in the atmosphere it is found. Ozone is naturally produced in the stratospheric portion of Earth's atmosphere (in the ozone layer) by the action of high-energy ultraviolet radiation on molecular oxygen (O 2 ). By absorbing much of the Sun's ultraviolet radiation, the ozone layer serves as a sunscreen for organisms on Earth. In recent years the ozone has thinned or disappeared in parts of the ozone layer, creating an ozone hole that lets in dangerous amounts of ultraviolet radiation. Ozone holes are caused in part by the release into the atmosphere of industrial and commercial chemicals, in particular the chlorofluorocarbons (such as freon) used in aerosols, refrigerants, and certain cleaning solvents. Closer to Earth's surface, ozone is one of the so-called greenhouse gases that are produced by the burning of fossil fuels and cause the greenhouse effect. Ozone at ground level is also an air pollutant, contributing to respiratory diseases such as asthma.

Example Sentences

Research suggested that air pollution from China contributes to up to 65 percent of the ozone increase in the Western United States.

From Time

That stark variety of regional effects was evident in, for example, the different post-pandemic ozone levels in Denver and New York City.

From Science News

The researchers determined that the chemical is formed when a preservative known as 6PPD reacts with ozone.

From Popular-Science

At this elevation, ozone protects life on Earth from the sun’s harmful ultraviolet radiation.

From Science News For Students

Eastern San Diegans also live with more exposure to harmful ozone, a natural and important part of our atmosphere that turns deadly when it’s mixed with car pollution and sunlight.

From Voice of San Diego

Air pollution gets worse during drought; in California the problem is soot, and in Texas it was ozone.

From The Daily Beast

Soot, methane, ozone, and HFCs are a lot less sexy than flying to Rio and making bold promises.

From The Daily Beast

Obama enraged his base last week by nullifying an environmental regulation on ozone.

From The Daily Beast

His first choice was Shri Trimurti Bhavan in Ozone Park, a temple where his uncle is a priest.

From The Daily Beast

The screening can be canceled, but people in Richmond Hill and Ozone Park still have ways to see it.

From The Daily Beast

Nothing—nothing but the smell of ozone and an echo bouncing crazily off the walls of the conduit.

From Project Gutenberg

He discharged the accumulated energy in a single blue flare that filled the lab with thunder and ozone.

From Project Gutenberg

The Adriatic on our right, not near enough to see, but the air seemed impregnated with its ozone.

From Project Gutenberg

Let the sun put its coat of health on you, and let the ozone put the red blood of strength in your veins.

From Project Gutenberg

It was the season of fierce heat, but we faced the northern breezes full of invigorating ozone.

From Project Gutenberg

Related Words

• atmosphere
• breeze
• wind