Which of the following is closest to the wavelength of a prominent spectral line for lithium chloride (LiCl) observed in the visible region?

• A. 670 nm
• B. 450 nm
• C. 320 nm
• D. 1200 nm

Answer: (A)

Verified step by step guidance

1. Understand that the problem is asking for the wavelength of a prominent spectral line of lithium chloride (LiCl) in the visible region. Visible light wavelengths range approximately from 400 nm to 700 nm.
2. Recall that spectral lines correspond to electronic transitions or molecular vibrations/rotations that emit or absorb light at specific wavelengths. For LiCl, a diatomic molecule, the prominent spectral lines in the visible region are often due to electronic transitions.
3. Identify that the given options are 450 nm, 320 nm, and 1200 nm. Since 320 nm is in the ultraviolet region and 1200 nm is in the infrared region, these are less likely to be visible spectral lines.
4. Recognize that 670 nm falls within the red portion of the visible spectrum, making it the most plausible wavelength for a prominent visible spectral line of LiCl.
5. Conclude that the wavelength closest to the prominent spectral line of LiCl in the visible region is 670 nm, based on the typical visible spectrum range and the nature of molecular spectral lines.