Question

Ozone is an important constituent of stratosphere because it: (a) Removes poisonous gases of the atmosphere by reacting with them (b) Destroys bacteria which are harmful to human life (c) Prevents the formation of smog over large cities (d) Absorbs ultraviolet radiation which is harmful to human life

Short answer

(d) Absorbs ultraviolet radiation which is harmful to human life.

Step-by-step solution

Understand the Role of Ozone in the Stratosphere

Ozone in the stratosphere plays a crucial role primarily due to one key function: its ability to absorb ultraviolet (UV) radiation. The \( O_3 \) molecules absorb the UV rays, which prevents these harmful rays from reaching the Earth's surface.

Evaluate Each Given Option

Let's assess each option to see how it aligns with the function of stratospheric ozone: - (a) This option suggests that ozone removes poisonous gases by reacting with them, which is not its primary role in the stratosphere. - (b) Although ozone has disinfectant properties, its protective role in the stratosphere is not about destroying bacteria. - (c) Prevention of smog formation is not related to the function of stratospheric ozone. - (d) This aligns exactly with the role of ozone: absorbing harmful ultraviolet (UV) radiation.

Choose the Correct Answer

After evaluating all options, option (d) is consistent with the primary role of ozone in the stratosphere: to absorb ultraviolet radiation, protecting life on Earth from its harmful effects.

Key concepts

Stratospheric Ozone

The stratospheric ozone layer is a region located in the Earth's stratosphere, which lies approximately 10 to 30 miles above the Earth's surface. Ozone, scientifically notated as \( O_3 \), is a molecule made up of three oxygen atoms. The presence of ozone in this layer is essential due to its ability to shield the Earth from harmful solar radiation. It acts as a blanket, filtering out the majority of the sun’s harmful ultraviolet rays. This particular concentration of ozone, often called the "ozone shield," is crucial for maintaining a balanced ecosystem on our planet.
Without this protective layer, life on Earth, as we know, would be severely threatened because of increased exposure to UV radiation. The chemical reactions that create ozone in the stratosphere occur when UV light strikes regular oxygen molecules \( O_2 \) and split them apart, which then recombine with other oxygen molecules to form ozone molecules.

Ultraviolet Radiation Absorption

One of the most vital functions of the stratospheric ozone layer is its ability to absorb ultraviolet (UV) radiation. UV rays are parts of the electromagnetic spectrum emitted by the sun, and they can have damaging effects on living organisms. This absorption process is critical because it significantly reduces the amount of UV radiation that penetrates the Earth's atmosphere.
Ultraviolet radiation is classified into three types:

• UVA: Longer wavelength and less harmful, these rays are not absorbed by ozone but still reach the Earth's surface.
• UVB: Partially absorbed by ozone, these rays are more intense and can lead to sunburns and skin cancers.
• UVC: The most harmful radiation, but completely absorbed by the ozone layer and the atmosphere before reaching the Earth.

Through these absorption capabilities, the ozone layer protects all terrestrial life by minimizing exposure to these harmful rays.

Environmental Protection

The role of stratospheric ozone in environmental protection cannot be overstated. By absorbing harmful UV radiation, it protects biological organisms, including humans, from potentially fatal overexposure to UV light. Ozone helps prevent various health problems, such as skin cancer, cataracts, and immune system suppression in humans.
Moreover, the ozone layer supports ecological systems by safeguarding plants and crops, which are sensitive to UV radiation. It ensures robust agricultural productivity and maintains the health of natural ecosystems, such as forests and oceans, by protecting phytoplankton and Pfueteriopankton, the base of aquatic food chains. As such, maintaining the stability of the ozone layer is vital for overall environmental protection and sustainability.
Efforts have been made globally to protect this layer, most notably through the Montreal Protocol, an international treaty aimed at phasing out substances that deplete the ozone layer.

Ozone's Protective Role

Ozone’s protective role is primarily visible through its function as a natural sunscreen for our planet. By forming a layer that absorbs most of the UV radiation, it prevents these harmful rays from exerting full force on living organisms. This ensures that life on earth is not exposed to the harmful effects of excessive UV radiation, such as genetic damage in living cells.
Beyond human health implications, this protective role extends to preserving the climate balance by sustaining natural habitats and biodiversity. Without the ozone layer, the delicate balance of our ecosystems would be disrupted, leading to dire consequences for biodiversity and human existence.
It is critical to understand and appreciate the significance of this natural shield. This understanding fosters a sense of responsibility in us to protect and sustain the ozone layer by minimizing activities that contribute to its depletion, ensuring that it continues to perform its vital function for generations to come.