Chemical reactions cannot produce x-rays.

physical effect

1. Penetration refers to the ability of X-rays to pass through a substance without being absorbed. X-rays can penetrate substances that ordinary visible light cannot penetrate. Because of its short wave length and high energy, when X-rays irradiate on matter, only a part of them are absorbed by matter, and most of them pass through atomic gaps, showing strong penetration ability. The ability of X-rays to penetrate matter is related to the energy of X-ray photons. The shorter the wavelength of X-ray, the greater the photon energy and the stronger the penetrating power. X-ray penetration is also related to the density of matter. Substances with high density absorb more X-rays and transmit less. Low density has less absorption and more penetration. Using the characteristics of differential absorption, soft tissues such as bones, muscles and fat with different densities can be distinguished. This is the physical basis of X-ray fluoroscopy and photography.

2. When the ionized substance is irradiated by X-rays, the electrons outside the nucleus leave the atomic orbit, which is called ionization. In the process of photoelectric effect and scattering, the process in which photoelectrons and recoil electrons leave their atoms is called primary ionization, and the process in which these photoelectrons or recoil electrons collide with other atoms in the process of traveling is called secondary ionization. In solids and liquids. Ionized positive and negative ions will recombine quickly and are not easy to collect. The forgotten charge in gas is easy to collect, and the X-ray exposure can be measured by ionizing charge: the X-ray measuring instrument is made according to this principle. Due to ionization, gas can conduct electricity; Some substances can react chemically; Various biological effects can be induced in organisms. Ionization is the basis of X-ray injury and treatment.

Fluorescence is invisible because the wavelength of X-ray is very short. However, when it irradiates some compounds such as phosphorus, platinum barium cyanide, zinc cadmium sulfide, calcium tungstate and so on. The atom is excited by ionization or excitation. When the atom returns to the ground state, it radiates visible light or ultraviolet light due to the energy level transition of valence electrons. This is fluorescence. X-rays make substances fluoresce, which is called fluorescence. The intensity of fluorescence is directly proportional to the number of x-rays. This function is the basis of X-ray application in perspective. This fluorescence can be used for X-ray diagnosis, making fluorescent screen, intensifying screen, input screen of image intensifier, etc. Fluorescent screen is used to observe the image of X-rays passing through human tissues during fluoroscopy, and intensifying screen is used to enhance the sensitivity of film during photography.

4. Most of the X-ray energy absorbed by hot matter is converted into heat energy, which raises the temperature of the object. This is a thermal action.

5. Interference, diffraction, reflection and refraction are the same as visible light. It has been applied to X-ray microscope, wavelength measurement and material structure analysis.

(2) Chemical effects

1. Photosensitization is the same as visible light, and X-rays can make films photosensitive. When silver bromide on the film is irradiated by X-rays, silver particles can be precipitated, and the film will have a "photosensitive effect". The photographic intensity of film is in direct proportion to the number of x-rays. When X-rays pass through the human body, the density of each tissue in the human body is different, the absorption of X-rays is different, and the sensitivity obtained on the exposed film is also different, thus obtaining X-ray images. This is the basis of using X-ray for photographic inspection.

2. Some substances play a coloring role, such as platinum, barium cyanide, lead glass, crystal, etc. Dehydration and discoloration after long-term X-ray irradiation is called coloring effect.

(3) Biological effects

When X-rays irradiate organisms, biological cells are inhibited, destroyed or even necrotic, which leads to different degrees of physiological, pathological and biochemical changes in organisms, which is called biological effect of X-rays. Different biological cells have different sensitivities to X-rays. Maple Leaf X-ray can treat some diseases of human body, such as tumor. On the other hand, it is harmful to normal body, so we should pay attention to the protection of human body. The biological effect of X-rays is caused by the ionization of X-rays. What we mean by chemical reaction is the reaction between atoms, that is, through the gain and loss of electrons between atoms, the old chemical bonds in the molecules are broken to form new chemical bonds, that is, atoms recombine to form new molecules. Radioactivity is only related to the nucleus, involving the inside of the atom, and is only determined by the nucleus, so chemical reactions cannot change radioactivity.