X-ray crystallography is the study of crystal structure by means of X-ray
diffraction. Each substance has a different crystalline structure. The atoms, molecules, or ions
in a far too small to affect a beam of light. X-rays, however, have a shorter wavelength than visible light and diffracted by the lattice.
X-ray crystallography allows the details of the structure to be recording by bombarding a crystal sample (1) with a beams of X-rays (2). The X-rays are created by bombarding a tungsten anode (3) with electrons in a vacuum (4). A slit (5) focusses the X-rays on the crystal. The distance between the atomic planes in the crystal either reinforces (6) or cancels out (7) the X-rays. When the ray is reinforced the emerging X-ray (8) creates a spot (9) on photographic film. The pattern of the spots can be used to deduce the exact structure of molecules.