Radioactive Decay

Radioactive Decay Some isotopes (atoms with the same # of _______ but different # of ________) are unstable, meaning their nuclei don’t hold together well In radioactive decay, radiation is spontaneously released from an atom’s nucleus in the form of different particles

Three Types of Radiation Alpha: ___ charge Beta: ___ charge Gamma: ____ charge

Alpha Particles Made up of 2 neutrons, 2 protons When an atom loses an alpha particle, its atomic number drops by 2 Polonium-210 (atm. #84)  Lead-206 (atm. #82)

Penetrating Power of Radiation

Radioactive Tracers Because radiation can be observed, a radioactive isotope can be used to follow the steps of a chemical reaction. Tracers are radioactive isotopes used to trace the steps of a reaction. Doctors use tracers to find medical problems and kill unhealthy cells. Ex: technetium-99 used to diagnose problems in bones, liver, kidneys

Cancer and Gamma Radiation After cancerous cells are located, doctors can use radioactive gamma rays to kill these harmful cells. High energy gamma rays, such as cobalt- 60 can be directed at cancerous tumors, causing a powerful change that can kill cancer cells.

Radioactive Carbon Dating Scientists can determine the age of natural materials found on earth by determining the half-life of certain atoms. The half-life of an isotope is the length of time needed for half of the atoms of a given sample to decay. It is different for different elements. Radioactive dating is the process of determining the age of an object by using the half-life of its radioactive isotopes. The most common isotope used to determine the age of a fossil is carbon-14.