To solve this question, the user needs to know the basics of atomic structure and how excited atoms emit photons when they return to their ground state.
An excited atom has excess energy and can release this energy as a photon when it returns to its ground state. The energy of the emitted photon is equal to the difference in energy between the excited state and the ground state.
The color of the emitted photon depends on its wavelength, which is related to its energy. Shorter wavelengths have higher energy and are associated with colors like blue and violet, while longer wavelengths have lower energy and are associated with colors like red and orange.
If the atom decays to an intermediate state before returning to its ground state, the energy of the emitted photon will be less than the energy difference between the excited state and the ground state. This means that the wavelength of the photon will be longer, and its color will be shifted towards the red end of the spectrum.
Now, let's go through each option and explain why it is right or wrong:
A. Blue: This option is incorrect because the energy of a photon emitted during the decay to the intermediate state will be less than the energy of the green photon emitted during decay to the ground state. This means that the wavelength of the emitted photon will be longer, shifting its color towards the red end of the spectrum.
B. Violet: This option is incorrect for the same reason as option A. The energy of the emitted photon will be less than the energy of the green photon, resulting in a longer wavelength and a color shift towards the red end of the spectrum.
C. White: This option is incorrect because white light is a combination of all colors in the visible spectrum. It is not a specific color that can be emitted by an atom during a transition.
D. Red: This option is correct. If the atom decays to an intermediate state, the energy of the emitted photon will be less than the energy of the green photon emitted during decay to the ground state. This means that the wavelength of the emitted photon will be longer, shifting its color towards the red end of the spectrum.
The Answer is: D