Question

Anatomy absorbs x-rays based on the density of the structure ( subject thickness).
why do some anatomical structures appear black, and others clear or white?
why do some structures allow more x-rays to pass through and energize the film crystals, while other structures do not?

Answer 1

Some anatomical structures appear black and others clear or white because different tissues absorb different of radiations.Calcium in the bones absorb more ,so that the bones look like white.Fat and some other tissues absorb less x-ray and look grey.Air in the lungs absorb the least and look black.

Some structure allow more x-rays to pass through and energize the film crystal because x-rays have the wavelength similar to the size of the atom that energize the film crystal .X rays contain more energy than the visible length .X-rays contain more wavelength than visible light.so they penetrate more easily than visible light.some structure do not energize the film because the wavelength is not similar to the size of the atom.