Which individual is personally trying to influence public policy?

You're question isn't completely specific, but if I'm reading correctly I would tell you that interest groups influence public policy through lobbying of their interests.  This is a group of individuals who sign petitions, protest, and voting for example. I hope this helped :)

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.