def get_element_mass(self, element):
result = [<NUM_LIT:0>]<EOL>for compound in self.material.compounds:<EOL><INDENT>c = self.get_compound_mass(compound)<EOL>f = [c * x for x in emf(compound, [element])]<EOL>result = [v+f[ix] for ix, v in enumerate(result)]<EOL><DEDENT>return result[<NUM_LIT:0>]<EOL>
Determine the masses of elements in the package.

:returns: [kg] An array of element masses. The sequence of the elements
  in the result corresponds with the sequence of elements in the
  element list of the material.