Oxygen is O2. Ozone is O3.

Oxygen is an element (Atomic number 16). Ozone is a gaseous molecule consisting of three Oxygen atoms bonded together.

1) "In science, oxygen (IPA: /ˈɒkË‘səˑdʒɪn/) is a chemical element with the chemical symbol O and atomic number 8. The word oxygen derives from two roots in Greek, οξύς (oxys) (acid, lit. sharp) and -γενής (-genÄ“s) (producer, lit. begetter). It was recognized in 1777 by Antoine Lavoisier, who coined the name oxygen from the Greek roots mentioned above because he erroneously thought that it was a constituent of all acids. (The definition of acid has since been revised). Oxygen has a valency of 2. On Earth it is usually bonded to other elements covalently or ionically. Examples for common oxygen-containing compounds include water (H2O), sand (silica, SiO2), and rust (iron oxide, Fe2O3). Diatomic oxygen (O2) is one of the two major components of air (20.95%). It is produced by plants during photosynthesis, and is necessary for aerobic respiration in animals. It is toxic to obligate anaerobic organisms and was a poisonous waste product for early life on Earth. Triatomic oxygen (ozone, O3) forms through radiation in the upper layers of the atmosphere and acts as a shield against UV radiation." Source and further information: http://en.wikipedia.org/wiki/Oxygen Further information: http://en.wikipedia.org/wiki/Ozone 2) Oxygen is the name given to either the chemical element O, the diatomic molecule O, or the gas (a lot of these molecules!). On earth, the chemical element is mainly found in some kind of molecule, normally not alone.

my answer is this: ozone is posinous when it is in our atmosphere. Oxygen is not.. Ozone is not stable as CFC decompose it into Oxygen whereas Oxygen is stable. Ozone (when in the stratosphere) protects us from harmful Uv rays which cause skin cancers and eye cataracts whilst Oxgen does not..