Chemistry
The Chemistry of Photochemical Smog: NOx in Atmospheric Ozone Generation
Quick fact
A single molecule of nitrogen dioxide can generate many molecules of ozone without being consumed, because it is regenerated in a catalytic cycle—this is why even small amounts of NOx can drive significant smog formation.
Why this is interesting
Ever wondered why summer afternoons in cities often bring hazy skies and itchy eyes? The culprit might be a chemical dance between nitrogen oxides and sunlight—a process that turns clear air into a toxic brew.