Radioactive dating real
Cosmic radiation from the Sun and other stars is a source of background radiation on Earth.
Uranium and thorium also occur in trace amounts in water.
Radiotherapy commonly is used to treat cancer and other conditions involving abnormal tissue growth, such as hyperthyroidism.
Beams of subatomic particles, such as protons, neutrons, or alpha or beta particles, directed toward diseased tissues can disrupt the atomic or molecular structure of abnormal cells, causing them to die.
Other radioactive isotopes are used as tracers for diagnostic purposes as well as in research on metabolic processes.
When a radioactive isotope is added in small amounts to comparatively large quantities of the stable element, it behaves exactly the same as the ordinary isotope chemically; it can, however, be traced with a Geiger counter or other detection device.