def parseLine(line):
  """
    Parse composition line by deleting whitespace and separating the isotope and atomic density.
    @ In, line, string, line of isotope and composition
    @ Out, result, tuple, (isotope, atomic density)
  """
  line = line.lstrip()
  isotope, atomDensity = line.split("  ")
  result = (isotope, float(atomDensity))
  return result