Question

Which gas in the atmosphere protects us from ultraviolet rays?

• A. Nitrogen
• B. Oxygen
• C. Ozone
• D. Carbon monoxide

Hint:

Think of the stratospheric layer that is thinned by the ozone hole.

Answer 1

The Correct Option is C

Step 1: The Sun sends out ultraviolet (UV) radiation along with visible light. Large amounts of UV reaching the ground can damage skin and eyes and harm living cells.

Step 2: High up in the atmosphere, in a layer of the stratosphere roughly 15 to 35 km above the ground, oxygen molecules absorb UV energy and split into single oxygen atoms. These atoms then combine with other oxygen molecules to form ozone, a molecule made of three oxygen atoms.

Step 3: This layer of ozone strongly absorbs incoming UV-B and UV-C radiation from the Sun, converting it into heat, and stops most of it from reaching the surface of the Earth.

Step 4: Nitrogen is chemically inert and does not absorb UV in this way. Carbon monoxide is a pollutant and plays no role in filtering sunlight. Oxygen alone absorbs only a small part of UV compared to ozone.

Answer: Ozone, option C.