Which region of the electromagnetic spectrum is most strongly absorbed by liquid water?

• A. Visible
• B. Infrared
• C. Microwave
• D. Ultraviolet

Answer: (B)

Verified step by step guidance

1. Understand that different regions of the electromagnetic spectrum correspond to different types of molecular interactions and energy transitions.
2. Recall that liquid water absorbs electromagnetic radiation primarily due to molecular vibrations and rotations, which correspond to specific energy ranges.
3. Recognize that the infrared region of the spectrum is associated with vibrational transitions in molecules, including the O-H bonds in water.
4. Note that visible light is mostly transmitted through water with little absorption, while ultraviolet light can cause electronic transitions but is less absorbed by liquid water compared to infrared.
5. Conclude that because water molecules strongly absorb radiation that causes vibrational excitation, the infrared region is most strongly absorbed by liquid water.