Nucleation

In the context of air pollution, nucleation is the first step of the process by which gases are converted to small liquid droplets (ultrafine particles).

This occurs either when certain gases condensate or when different gases react with each other.

The ultrafine particles formed are called "nuclei" and can grow in size when more gases condensate on them or when several droplets merge.

Source: GreenFacts

Fine particles - Particulate matter

Ozone

Particulate Matter

Nitrogen Dioxide

Climate Change