What isotope is used for radioactive dating
At time t = 0, the hourglass is turned upside-down so that all the sand starts in the top bowl.
Thus the first step in the radioactive dating technique is to measure the amounts of the parent and daughter elements (isotopes) in a rock sample via chemical analyses.
This is done in specially equipped laboratories with sophisticated instruments capable of very good precision and accuracy, so in general there is no quarrel with the resulting chemical analyses.
However, it is with the interpretation of the chemical analyses of the radioactive parents and resultant daughters that the problems with radioactive dating of rocks begin.In order to interpret these chemical analyses, geochronologists must make three vital assumptions, otherwise the radioactive ‘clock’ cannot be made to ‘read’ the ‘age’ of the rocks.