How thick does carbon need to be in atoms be able to absorb all light a

Jan 2016
When a atom absorbs, and transmissions light, I
have been told that single atoms are transparent, whatever the element.
So how many atoms thick in carbon does it take to
completely absorb all wavelength, and frequency of light.
Is it basically as you increase the amount of atoms in a crystalline, or non crystalline structure, there is just too many electron absorbing the amount of photons hitting, and getting absorbed by the electrons, and light just cannot get through.
The light just gets absorbed weather the material is amorphous, or not.
So its only the energy of electron that will let light pass, and transmission through like in glass, and carbon diamond
Is this correct.
Thank you for your help, anything helps, even a few words.