Introduction to alpha particles
Alpha particles are particles emitted by certain radioactive materials when they decay. They are composed of two neutrons and two protons (helium-4). The mass is four times that of hydrogen atoms. The speed can reach 20,000 kilometers per second, with a positive charge. . The penetrating power is not great and can damage the animal's skin.
Alpha particles are positively charged high-energy particles (He-4 nuclei), which quickly lose energy after passing through the medium. They are usually produced by the decay of some heavy atoms (eg uranium, radium) or some artificial nuclides. Alpha particles run in the medium, quickly lose energy, and cannot penetrate far. However, penetration into the tissue (even if it cannot be penetrated) can cause tissue damage. Alpha particles are usually completely absorbed by the outer necrotic skin of the human body, and the radioisotopes released by the alpha particles do not pose a danger outside the human body. However, once they are inhaled or injected, it will be very dangerous. Alpha particles can be blocked by a thin piece of paper.