Question

Compare and contrast the observations from the flame tests, the emissions tubes, and the LEDs. Why do different spectra observed make sense in relation to each other? What may be the cause of differences between different methods? Some things you may want to consider are line widths, use of various compounds or elements, and composition of materials.

Answer 1

Flame test is one of the direct method where emission spectra of a compound is seen due to excitation of electrons from one energy level to the other. This test helps in knowing the ions present in the given Compound I,e the composition of the compound qualitatively.

Emission tubes are rhw discharge tubes where in the compound is taken in its gas phase and high voltage supply is given and the spectra is observed through diffraction gratings. Again this is also due to electronic transitions.

LED is again a light emitting diode which again emmits light. I,e an emmision spectra from a semiconductor. It has a continuous spectrum with dark lines at some intervals.

Comparison of all the three give in common factor of being emission spectra.

Contrast off all the three is they use different form of a matter to emit light like flame test uses a solid. Emission tubes uses gas phase while LED uses a semiconductor Solid or molten state of a matter.