Is ozone a stable or unstable molecule in the stratosphere?

Ozone is considered an unstable molecule in the stratosphere due to its relatively high reactivity compared to molecular oxygen (O2). While ozone does have a vital role in absorbing ultraviolet (UV) radiation and protecting life on Earth, it is composed of three oxygen atoms, making it less stable than the diatomic oxygen molecule.

The instability arises from the nature of the ozone molecule, which can break down through photodissociation or react with certain substances, such as volatile organic compounds or nitrogen oxides. This reactivity is essential for ozone’s function in the atmosphere but also makes it prone to decomposition and transformation into other components. Therefore, classifying ozone as unstable reflects its dynamic behavior in the stratosphere, where it constantly forms and breaks down in response to sunlight and other atmospheric conditions.

The other options do not accurately capture the chemical behavior of ozone, as it is primarily characterized by its reactivity and tendency to change rather than being stable, neutral, or variable in nature.