atomic_weights = {
    "H": 1.008,
    "He": 4.0026,
    "Li": 6.94,
    "Be": 9.0122,
    "B": 10.81,
    "C": 12.011,
    "N": 14.007,
    "O": 15.999,
    "F": 18.998,
    "Na": 22.99,
    "Mg": 24.305,
    "Al": 26.982,
    "Si": 28.085,
    "P": 30.974,
    "S": 32.06,
    "Cl": 35.45,
    "K": 39.098,
    "Ca": 40.078,
    "Fe": 55.845,
    "Cu": 63.546,
    "Zn": 65.38,
    "Ag": 107.868,
    "Au": 196.967
}