Why can hospital X-rays take pictures of bones and teeth?

X-rays are electromagnetic waves with very short wavelengths, much shorter than visible light. Like other electromagnetic waves, X-rays also have wave-particle duality, that is, they have the characteristics of both waves and particles. Human soft tissues and bones have different abilities to absorb X-rays, so X-rays can be used to examine human body structures. \x0d\When conducting X-ray examinations in hospitals, doctors took advantage of several of its characteristics: first, it has a high penetrating ability and can directly penetrate the human body; second, it can cause visible damage to many solid materials. Fluorescence, called the fluorescence effect, is the basis of X-ray perspective; finally, it can also make photographic films sensitive to light, which is the physical principle of X-ray photography. \x0d\When doctors take X-rays, they place photosensitive films underneath the human body. When X-rays pass through the human body, the calcium contained in tissues such as bones and teeth will absorb part of the rays, reducing the number of X-rays reaching the film, thus leaving the shadow of the tissue on the film. It's like a person's shadow in the sun. The first human X-ray film was a close-up of the hand bones taken by the great German scientist R?ntgen for his wife. In fact, not only bones, but also other objects that can absorb X-rays will leave their shadow on the photosensitive film. X-rays are such magical rays.