Hi David,

Actually, even the smallest atom can emit light in the visible range. The limit seems to be with our ability to detect it.

The lightest atom of all, the hydrogen atom can emit in the violet, blue and red frequencies.

For us to be able to see the red frequency of the hydrogen atom for example, which has a wavelength of 656 nanometers, it seems that at least 3 such photons need to hit one of the cells of our retina for us to be able to perceive this color.

In reality, one photon is emitted each time electrons jump back from the various fixed distances above their rest orbital in which they can momentarily stabilize after having been excited by themselves being hit by an incoming photon.

That's how light is produced. We perceive only a smal range of the actual wavelengths range, from about 380 nm to 750 nm. Longer and shorter wavelength are invisible to us. Our optic cells just can't detect them.

Dear Andre,

Thank you for your enlightening answer. So can it be said that hydrogen itself has a color? Or does it technically have all three colors?

Dear David,

Actually, the hydrogen atom can emit in each of these colors at different times.

Since the hydrogen atom has only one electron, then it can produce only one color at a time.

If you look up the Balmer series, you will be able to identify the three colors it can emit and their wavelengths in nanometers (nm), or possibly in Angstrom ( Å ). One nm = 10 angstroms, so if you see for example, 656 nm, it is the same as 6560 angstroms, and the reverse.

if you look up "visible light", you should get a chart of the ranges of wavelengths for each color in the visible range.

If you look for the spectral series for each atom, you will get their possible wavelengths.

The same for all larger molecules. That's how they identify the composition of unknown substances, for police work and archeological research, and all other fields.

In the visible range