Why are only certain colors of the emission spectrum in Hydrogen visible?
The human retina can detect only a certain range of wavelengths of light, corresponding to electronic transition energies of the pigment molecules in the rod and cone cells. Some other animals may have a vision that can detect wavelengths outside that range. The main point: it's not the hydrogen atom's fault that we don't see its whole emission spectrum, you have to blame evolution for that.
@Toleisnon Have you done any research on this?
I don't think that is correct. It IS the hydrogen atom's fault ... it doesn't emit a full spectrum, which is what the OP would have found if he had done any research.
It looks like we need clarification on what question you are asking. Are you asking why hydrogen only emits certain frequencies instead of all of them, or are you asking why we only see (with our eyes) certain frequencies among those that hydrogen does emit?
*Why hydrogen only emits certain frequencies when viewing it under a high school spectroscope instead of all of the frequencies (spectral lines)*
Sounds like you want the answer to both questions that Peter pointed out. I have answered one of them in post #4 and Hilbert answered the other in post #2. What about these answers is not clear to you?
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