Ozone
A)formation is promoted by CFCs.
B)is broken down by carbon dioxide.
C)is a source of oxygen for cellular respiration.
D)protects Earth from ultraviolet radiation.

Question

Quizplus · Accepted Answer

Ozone is a molecule composed of three oxygen atoms (O3). It is found in the stratosphere, a layer of Earth's atmosphere between 10 and 50 kilometers above the surface. Ozone absorbs most of the sun's harmful ultraviolet (UV) radiation, preventing it from reaching the surface of the planet where it can cause skin cancer, cataracts, and other problems. This is why ozone is often referred to as "Earth's sunscreen." However, ozone depletion occurs due to human activities, such as the emission of chlorofluorocarbons (CFCs), which can break down ozone molecules. Therefore, A is incorrect. Carbon dioxide does not break down ozone; in fact, carbon dioxide and other greenhouse gases can contribute to global warming, which affects the concentration of ozone in the atmosphere. Also, while oxygen is a component of ozone, it is not a source of oxygen for cellular respiration. Therefore, C is also incorrect.