What fundamental principle is based on the fact that each solid crystalline substance produces its own characteristic x-ray pattern?

The principle that each solid crystalline substance produces its own characteristic x-ray pattern is rooted in X-ray diffraction examination. This technique relies on the wave nature of X-rays, which, when directed at a crystalline material, interact with the lattice structure of the crystals. The periodic arrangement of atoms in the crystal causes the incident X-rays to be scattered in specific directions, creating a unique diffraction pattern that reflects the arrangement of the atoms.

This pattern is useful because it can be used to identify the material and determine its structural characteristics. Every crystalline material has a distinct atomic arrangement, leading to a unique diffraction pattern that can be measured and analyzed.

In contrast, the other options—X-ray fluorescence examination, X-ray absorption examination, and gamma ray spectroscopy—are based on different principles. X-ray fluorescence involves the emission of characteristic X-rays from a material when it is excited by a primary X-ray beam, while X-ray absorption examines how different materials absorb X-rays at varying energies. Gamma ray spectroscopy, on the other hand, pertains to the study of the energy and intensity of gamma rays emitted from radioactive materials. Each of these techniques serves different purposes and relies on different interactions between radiation and matter, making them distinct from the principle of X-ray diffraction.