If an average O₃ molecule “lives” only 100–200 seconds in the stratosphere before undergoing dissociation, how can O₃ offer any protection from ultraviolet radiation?

Verified step by step guidance

1. Step 1: Understand the role of ozone (O₃) in the stratosphere. Ozone absorbs harmful ultraviolet (UV) radiation from the sun, preventing it from reaching the Earth's surface.
2. Step 2: Recognize that the ozone layer is a dynamic system. Although individual O₃ molecules have a short lifespan, the continuous formation and destruction of ozone maintain a stable concentration in the stratosphere.
3. Step 3: Learn about the ozone-oxygen cycle. Ozone is constantly being formed and destroyed in the stratosphere through a series of reactions involving oxygen molecules (O₂) and oxygen atoms (O).
4. Step 4: Consider the balance between ozone formation and destruction. The rate of ozone formation is approximately equal to the rate of its destruction, ensuring a steady state concentration of ozone that can effectively absorb UV radiation.
5. Step 5: Reflect on the importance of this balance. Despite the short lifespan of individual ozone molecules, the overall concentration of ozone in the stratosphere is sufficient to provide significant protection from UV radiation.