code: def max_electronegativity(self):
          '''
          returns the maximum pairwise electronegativity difference
          '''
          maximum = 0
          for e1, e2 in combinations(self.elements, 2):
              if abs(Element(e1).X - Element(e2).X) > maximum:
                  maximum = abs(Element(e1).X - Element(e2).X)
          return maximuf max_electronegativity(self):
          '''
          returns the maximum pairwise electronegativity difference
          '''
          maximum = 0
          for e1, e2 in combinations(self.elements, 2):
              if abs(Element(e1).X - Element(e2).X) > maximum:
                  maximum = abs(Element(e1).X - Element(e2).X)
          return maximum
docs: returns the maximum pairwise electronegativity difference