6. An electron in a hydrogen atom drops from energy level E6 to energy level E3. What is the frequency of the emitted photon, and in which range of the the electromagnetic spectrum is this photon?

7. The energy-level diagram in Figure 2.10 shows the first five energy levels for mercury vapor. The energy of E1 is defined as zero. What is the frequency of the photon emitted when an electron drops from energy level E5 to E1 in a mercury atom?

E1 = 0 eV

E2 = 4.66 eV

E3 = 4.86 eV

E4 = 5.43 eV

E5 = 6.67 eV

8. How many different spectral lines could be emitted if mercury vapor were excited by photons with 6.67 eV of energy? (Hint: An electron could move, for example, from energy level E5 to E3 , then from E3 to E2 , and then from E2 to E1.)

9.. The emission spectrum of hydrogen has one emission line at a frequency of 7.29 1014 Hz. Calculate which two energy levels electrons must jump between to produce this line, and identify the line in the energy-level diagram in Sample Problem C. (Hint: First, find the energy of the photons, and then use the energy-level diagram.)