sentences:  A semi-empirical method for the prediction of reactivity ratios is called the Q-e scheme which was proposed by Alfrey and Price in 1947.This involves using two parameters for each monomer, formula_83 and formula_84.The reaction of formula_85
  radical with formula_86 monomer is written as
  
  formula_87
  
  while the reaction of formula_85 radical with formula_85 monomer is written as
  
  formula_90
  
  Where Q is the measure of reactivity of monomer via resonance stabilization, and e is the measure of polarity of monomer (molecule or radical) via the effect of functional groups on vinyl groups.