Ozone

How to spell ozone

5 letters · 2 syllables

How to pronounce ozone

Say the part in capitals loudest.

What does ozone mean?

1. nounA pale blue gas, a form of oxygen with three atoms per molecule, that forms a protective layer high in the atmosphere and is also a pollutant at ground level.

Ozone in a sentence

• The report warned that the ozone layer was thinning over the poles.

• High traffic levels push ground-level ozone to unhealthy concentrations in summer.

Where does ozone come from?

Language of origin: Greek

Ozone comes from the Greek verb ozein, meaning 'to smell', a fitting source because the gas has a sharp, distinctive odour that you can often notice near electrical sparks or after a thunderstorm. The name was coined in 1840 by the German-Swiss chemist Christian Friedrich Schönbein, who built the German word Ozon directly on that Greek root after he detected the pungent smell produced during electrolysis. English adopted the word almost immediately as 'ozone', keeping the Greek smell-root at its heart. The final '-one' is not the chemical ketone suffix but simply reflects the Greek participial ending; this is why the word looks like it should rhyme with 'gone' yet is pronounced 'oh-zone'. The same ozein root also lies behind the rarer scientific term 'ozostomia', meaning bad breath, which keeps the original 'smell' meaning very literal.

How the word is built

• oz- (from Greek ozein: to smell)
• -one (chemical suffix)