To be sure that the color is due to sodium, do a
flame test. This is used to identify the presence of small number of metal ions
in a compound. For sodium, the brilliant color of bright yellow is a result of
an excited electron in a very high level of energy and fall to a lower level called
the ground state.
In
addition, metals have different jump sizes in the energy level and
this means that each different metal will have a different pattern of spectral
lines, which results to different flame color.
