Diffraction grating placed in front of a slit of light from an incandescent bulb gives a rainbow.

    Excitation of hydrogen gas by high voltage electrons yields light of specific colors when observed through a diffraction grating.

    Excitation of mercury vapor by high voltage electrons yields light of specific colors when observed through a diffraction grating. The same colors are observed to each side of the central source.

    Excitation of a gas by high voltage electrons yields light of specific colors when observed through a diffraction grating. Gases used are (1) hydrogen, (2) helium, (3) mercury, and (4) nitrogen. N2 exhibits broader lines due to molecular vibrations and rotations in addition to electronic transitions.

    Diffraction grating placed in front of excited noble gases. The grating is oriented so that diffraction occurs vertically.

    Diffraction grating placed in front of excited noble gases, one gas at a time. The grating is oriented so that diffraction occurs horizontally.

    Excitation by chemical explosion.

    Excitation by chemical explosion.

    How do you think these colors are produced?

    Some of the colors available from a tricolor LED.

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