Ozone

An oxygenElement that makes up 20.95 vol. % of the Earth's atmosphere at ground level, 89 wt. % of seawater and 46.6 wt. % (94 vol. %) of Earth's crust. It appears to be the third most abundant element in the universe (after H and He), but has an abundance only Click on Term to Read More moleculeCollection of atoms held together by chemical bonds into a discrete, finite structure. One way molecules are represented is by a chemical formula where symbols for the elements are used to indicate the types of atoms present and subscripts are used to indicate the relative numbers of atoms. For example, Click on Term to Read More (O₃) composed of three oxygen atoms.