Which molecule in the atmosphere is primarily responsible for blocking harmful ultraviolet (UV) radiation from the Sun?

• A. Carbon dioxide (CO_2)
• B. Ozone (O_3)
• C. Nitrogen (N_2)
• D. Methane (CH_4)

Answer: (B)

Verified step by step guidance

1. Identify the role of each atmospheric molecule listed in the problem: Carbon dioxide (CO_2), Ozone (O_3), Nitrogen (N_2), and Methane (CH_4).
2. Recall that ultraviolet (UV) radiation from the Sun can be harmful to living organisms and that the atmosphere contains molecules that absorb or block this radiation.
3. Understand that Ozone (O_3) is a molecule composed of three oxygen atoms and is found primarily in the stratosphere, forming the ozone layer.
4. Recognize that the ozone layer absorbs the majority of the Sun's harmful UV radiation, preventing it from reaching the Earth's surface.
5. Conclude that among the given options, Ozone (O_3) is the molecule primarily responsible for blocking harmful ultraviolet (UV) radiation from the Sun.