Chemistry 2009 JAMB Past Questions - Question 34: The gas that is most useful in protecting humans against solar radiations is

Correct Answer

B

Explanation

The gas that plays the most crucial role in protecting humans from harmful solar radiation is **ozone (O₃)**. It filters out a significant portion of the sun's ultraviolet (UV) radiation, particularly the UVB rays which are the primary cause of sunburn and contribute to skin cancer risks.

Here's a breakdown of ozone's role:

* **Location:** Ozone concentration is highest in the stratosphere, around 15-35km above Earth's surface, forming the "ozone layer."
* **Mechanism:** Ozone absorbs UV radiation, converting it into heat that dissipates in the stratosphere. This prevents most UVB and a significant portion of UVA radiation from reaching the Earth's surface.
* **Importance:** Without the ozone layer, life on Earth would be exposed to much higher levels of harmful UV radiation, leading to increased risks of skin cancer, cataracts, and damage to ecosystems.

While other factors like the Earth's magnetic field and atmosphere also contribute to solar radiation protection, the **ozone layer is the primary shield** thanks to its specific absorption properties.