Someone pls answer this with steps

In the derivation of rrkm theory, a factor of 1/2 is introduced when equalizing the rates of formation and decomposition of activated complex as keal-hr) = ko this is clearly against the assumption of transition state theory that states all the activated complex in the transition state iss going to the product. find the reason why this factor is introduced here.

The substances that are necessary for producing of certain hormones and that store and transport vitamins

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this