Erstellt von Finnuala Brett
vor mehr als 6 Jahre
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Frage | Antworten |
Q: The mercury atoms in a fluorescent tube are excited and then emit photons in the ultraviolet region of the electromagnetic spectrum. i) Explain how the mercury atoms become excited. | A: i) The kinetic energy of the electrons passing through the tube transfers energy to the electrons in mercury atoms when colliding. This causes the orbital electrons to move to a higher energy level. |
ii) Explain how the excited mercury atoms emit photons. | ii) As the electrons become de-excited they emit photons equal to the energy difference between the levels. |
iii) Why do the excited mercury atoms emit photons of characteristic frequencies? | iii) Atoms have discrete energy levels; when electrons change levels they lose a discrete amount of energy. This means that photons of discrete frequencies are emitted. |
iv) Explain how the coating on the inside of a fluorescent tube emits visible light. | iv) The coating absorbs photons and re-emits photons of lower energy. |
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