A peroxy is composed of two O?, which aretightly bound together and inactive for all practical purposes. However, when aperoxy bond breaks, the rock becomes a semiconductor.

In the atmosphere, isoprene reacts with hydroxyl (OH) radicals, generating hydroxy-peroxy isoprene (RO 2) radicals, the breakdown of which can yield submicrometre-sized aerosols.

Compounds of particular interest include the hydroperoxy radical (HO 2) and organic peroxy radicals. Wood group members have conducted extensive fieldwork in major urban areas such as New York City, ...