NUCLEAR ENERGY
PROFESSIONAL(SPECIAL) ENGLISH COURSE
CHAPTER 3 Radioactivity
CHAPTER 3 Radioactivity（放射性）
Many naturally occurring and man-made isotopes have the property of radioactivity(放射性), which is the spontaneous(自发) disintegration (decay) (衰变) of the nucleus with the emission of a particle. The process takes place in minerals (矿物质) of the ground, in fibers (纤维) of plants, in tissues (组织) of animals, and in the air and water, all of which contain traces (痕迹,微量) of radioactive elements.
3.1  ...