If the emission spectrum of iodine displays bright lines at specific wavelengths, which of the following best describes its absorption spectrum?

• A. Dark lines appear at random wavelengths unrelated to the emission spectrum.
• B. Continuous spectrum with no lines present.
• C. Dark lines appear at the same wavelengths as the bright lines in the emission spectrum.
• D. Bright lines appear at all wavelengths except those in the emission spectrum.

Answer: (C)

Verified step by step guidance

1. Understand that an emission spectrum shows bright lines at specific wavelengths where atoms emit light as electrons drop from higher to lower energy levels.
2. Recognize that an absorption spectrum is formed when atoms absorb light at specific wavelengths, causing electrons to jump from lower to higher energy levels.
3. Recall that the wavelengths absorbed correspond exactly to the wavelengths emitted, because the energy differences between electron levels are the same for absorption and emission.
4. Therefore, the absorption spectrum will show dark lines (absorption lines) at the same wavelengths where the emission spectrum shows bright lines.
5. Conclude that the correct description of the absorption spectrum is that dark lines appear at the same wavelengths as the bright lines in the emission spectrum.