public void RemoveNonExistantIsotopeFromFromula()
{
ChemicalFormula formulaA = new ChemicalFormula("C2H5NO2");
ChemicalFormula formulaB = new ChemicalFormula("Fe");
ChemicalFormula formulaC = new ChemicalFormula("C2H5Fe-1NO2");
formulaA.Remove(formulaB);
Assert.AreEqual(formulaA, formulaC);
}