The chemical symbol of ___________ is O3.

The chemical symbol O3 represents ozone gas. Ozone is a molecule composed of three oxygen atoms, distinguishing it from the more common diatomic oxygen gas, which has the chemical symbol O2. Ozone exists naturally in the Earth's stratosphere and plays a crucial role in protecting life by absorbing the majority of the sun's harmful ultraviolet radiation.

In contrast, hydrogen gas consists of diatomic molecules represented by the symbol H2, carbon dioxide is a molecule made of one carbon and two oxygen atoms, denoted as CO2, and nitrogen gas features diatomic nitrogen molecules represented by N2. Understanding these chemical symbols is essential for recognizing the different properties and roles these gases play in various environmental and chemical processes.