T/F
The absorption lines of neon occur at slightly different wavelengths than its emission lines.
My answer: I thought that they would have the exactly opposite wavelengths? Am I missing something?
Your teacher probably wants False, it sounds very much like a beginning class in spectra.
In graduate school, you may learn about the Stark effect. Neon is normally ionized in gaseous tubes under very high electric fields, and the Stark effect is present, which splits the line spectra (slightly off of the emission spectra). https://en.wikipedia.org/wiki/Stark_effect
Your understanding is correct. The absorption lines of neon should occur at exactly the same wavelengths as its emission lines, but in the opposite sense. Allow me to explain how absorption and emission lines work to clarify any confusion.
When a light source, such as a neon gas, is heated or energized, its atoms absorb energy and undergo transitions to higher energy levels. This absorption process causes the atoms' electrons to move from lower energy levels to higher energy levels. These excited electrons in the higher energy levels are in an unstable state and will eventually drop back down to lower energy levels, returning the system to its ground state.
When the excited electrons return to lower energy levels, they release energy in the form of electromagnetic radiation (light). This emitted light corresponds to specific wavelengths that are determined by the energy difference between the electron's initial and final energy states. These specific wavelengths of light produce distinct emission lines.
On the other hand, when this same light source (neon gas) is placed in front of a continuous spectrum of light or a source of white light (such as from the Sun or a light bulb), the gas will absorb certain wavelengths of light. This occurs because the electrons in the neon atoms can absorb photons from the incident light that have the exact energy required to move the electrons up to higher energy levels. The absorbed wavelengths are then missing from the transmitted or observed light, resulting in dark absorption lines superimposed on the continuous spectrum or background.
Therefore, the absorption lines of neon should occur at the same wavelengths as its emission lines, but with the opposite sense. If you are finding information that indicates slightly different wavelengths, it is advisable to check your sources for accuracy.