Which of the following describes ozone?

• A. A molecule consisting of two oxygen atoms
• B. A molecule consisting of four oxygen atoms
• C. A molecule consisting of three oxygen atoms
• D. A molecule consisting of one oxygen atom

Answer: (C)

Ozone is a molecule formed by three oxygen atoms, making its chemical formula O₃. This specific structure is crucial because ozone plays a significant role in the Earth's atmosphere, particularly in the stratosphere, where it forms the ozone layer. The ozone layer is essential for absorbing the majority of the sun's harmful ultraviolet (UV) radiation, protecting living organisms on Earth.

The molecular structure of ozone distinguishes it from regular oxygen, which is found as O₂, a diatomic molecule consisting of two oxygen atoms. Understanding the differences in these molecular structures is vital for grasping the importance of ozone in both environmental science and regulations concerning substances that may deplete the ozone layer. The other options incorrectly describe the composition of ozone, either overstating or understating the number of oxygen atoms present.