Test Your Knowledge
Problem 1: Using the Bohr theory, compute the first four energy levels of hydrogen
4
3
2
1
Problem 2: Calculate the three longest wavelengths of hydrogen's visible emission
spectrum.
Problem 3: Can a 21 eV photon excite a hydrogen atom? If it can excite the atom, what
wavelength(s) will be seen in the emission spectra. Explain your reasoning
Problem 4: Can a 21 eV electron beam excite a hydrogen? If it can excite the atom, what
wavelength(s) will be seen in the emission spectra. Explain your reasoning
Problem 5: In a Franck-Hertz type of experiment atomic hydrogen is bombarded with
electrons, and excitation potentials are found at 10.21 V and 12.10 V.
A.
Explain the observation that three different lines of spectral emission accompany
these excitations.
B.
Find the wavelengths of the three spectral lines observed during the experiment.
Problem 6: Assume the angular momentum of the earth of mass 6.0x1024 kg due to its
motion around the sun at radius 1.5x1011 m to be quantized according to Bohr's
relationship.
A.
What is the value of the quantum number n?
B.
What is the fractional energy difference (E/E) between the orbital energy levels
of the earth?