system
Given the following post, respond as if you're commenting on Reddit:
human
Do different isotopes (e.g. Carbon 12 and Carbon 14) have slightly different electron emission spectra?

Do isotopes of atoms cause the electrons to have slightly different energy levels and therefore slightly different emission spectra or do the electron levels remain the same?
gpt
Their atomic spectra will be slightly different due to *isotope shift*. The nucleus is not actually a point as we often pretend in chemistry; it has some extended spatial structure. And different isotopes of the same element have different nuclear structure.

The finite size of the nucleus has a small influence on the atomic level structure, so if you change the structure of the nucleus (for example by adding a few neutrons), you change these very small shifts in the atomic spectrum.