Why can X-ray see through, what is the principle?

Because the energy of X-rays is greater than that of ordinary light, when irradiated on an object, only a part of it is absorbed by the material, and most of the X-rays can pass through the interatomic gap and have very strong penetrating power. The X-ray penetrating ability is positively correlated with the energy of the X-ray. The shorter the X-ray wavelength is, the greater the energy of the X-ray is, and the stronger the penetrating ability is. Therefore, we can see that the penetrating ability of X-rays is also related to the density of the object, so objects with different densities display different images.