Image taken from the years, scientists have managed to determine some general rules to predict how likely it is that an atom will undergo radioactive decay.
Cyber sex chat room in jamaica - Elements used for radioactive dating
Long-lived radioactive elements such as uranium, thorium and potassium and any of their decay products, such as radium and radon are examples of NORM.
These elements have always been present in the Earth's crust and atmosphere, and are concentrated in some places, such as uranium orebodies which may be mined.
For most human activities involving minerals and raw materials, the levels of exposure to these radionuclides are not significantly greater than normal background levels and are not of concern for radiation protection.
However, certain work activities can give rise to significantly enhanced exposures that may need to be controlled by regulation.
The alkali metals are the elements that make up Group 1 (IA) of the periodic table.