Radioactive rays harm us . So,how can radioactive rays given out by a nucleas,cure a disease like cancer?
In Cancer, the cells grow abnormally and out of control. In radiation therapy, high-energy X-rays are directed at a person's body to kill cancer cells and keep them from growing and multiplying. Radiation therapy delivers higher doses of radiation so that the radiation kills cancer cells and shrinks tumors. Radiation therapy works by damaging the genetic material within cancer cells and limiting their ability to successfully reproduce. When these damaged cancer cells die, the body naturally eliminates them. Normal cells are also affected by radiation, but they are able to repair themselves in a way that cancer cells cannot.