Ozone is a molecule made up of ________ oxygen atoms.

three

The correct answer is option 4. three.

Ozone (\(O_3\)) is a molecule composed of three oxygen atoms. The oxygen we breathe, which is diatomic oxygen (\(O_2\)), consists of two oxygen atoms sharing a double bond. Ozone, on the other hand, is a triatomic molecule formed by the presence of a third oxygen atom.

Ozone is typically formed in the Earth's stratosphere through the action of ultraviolet (UV) radiation from the Sun.

The process involves the dissociation of diatomic oxygen (\(O_2\)) into two oxygen atoms, and these oxygen atoms then combine with other \(O_2\) molecules to form \(O_3\) (ozone).

\[ O_2 + UV \rightarrow 2O \]

\[ O + O_2 \rightarrow O_3 \]

Ozone has a bent or V-shaped molecular structure, and each oxygen atom is bonded to the other two through a single bond.

\[ \text{O} - \text{O} - \text{O} \]

In summary, ozone is a triatomic molecule made up of three oxygen atoms (\(O_3\)). Its presence in the stratosphere is crucial for the protection of life on Earth by shielding against harmful UV radiation from the Sun.