1. 臭氧
Ozone is a colourless gas which is a form of oxygen. There is a layer of ozone high above the earth's surface.

1. a colorless gas (O3) soluble in alkalis and cold water
a strong oxidizing agent
can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)