Elements of Modern Physics
172
8. Discuss the energy level diagram of the valence electron in the sodium
atom. If the
2
P 1/2 to
2
S 1/2 transition corresponds to a wavelength of 5895.923
Å, what is the minimum energy of the bombarding electrons required to
excite this Na line? (Assume that the Na atoms are in the ground state.)
9. Using experimental information (Table 5.3) about the energy levels of Ag,
determine the minimum potential required across the x-ray tube, to excite
the K lines and the L lines. What are the wavelengths of the K α lines?
What are the frequencies of K and L absorption edges?
10. If the K α1 radiation from silver is incident on a material, what is the largest
Z value of the material for which the K electrons can be ejected (use
Moseley’s law)? What is the kinetic energy of the ejected electron for
Cu?
11. Given that the K-absorption edges for lead is 0.140 Å, and the minimum
voltage required for producing K lines in lead is 88.6 keV, determine the
ratio of h/e.
12. For Cu, determine the kinetic energy of the Auger electron for the transition
in which two vacancies are created in the L I shell in filling up a K-shell
vacancy (some simplifying assumptions may be required.)
13. Assuming that Na
+
and Cl
–
behave like hard balls or radii 1.0 Å and 1.8 Å
respectively (as far as repulsive forces are concerned), estimate the
dissociation energy for a NaCl molecule. The ionization potential of Na is
5.1 eV and the electron affinity for Cl is 3.8 eV.
14. For the HCl molecule, lines are found as v/c equal to 2944, 2926, 2908,
2866, 2844, 2821 cm
–1
. Determine the force constant for the vibrational
motion, and the distance of separation for the ions.
15. The rule of equal spacing is not strictly valid for the vibrational-rotational
band. Calculate the change in the energy if the moment of inertia in the
two vibrational states is different, say I 0 and I 1 . Estimate (I 1 – I 0 )/I 0 for
HCl for the states corresponding to the spectrum observed in Problem 14.
172
8. Discuss the energy level diagram of the valence electron in the sodium
atom. If the
2
P 1/2 to
2
S 1/2 transition corresponds to a wavelength of 5895.923
Å, what is the minimum energy of the bombarding electrons required to
excite this Na line? (Assume that the Na atoms are in the ground state.)
9. Using experimental information (Table 5.3) about the energy levels of Ag,
determine the minimum potential required across the x-ray tube, to excite
the K lines and the L lines. What are the wavelengths of the K α lines?
What are the frequencies of K and L absorption edges?
10. If the K α1 radiation from silver is incident on a material, what is the largest
Z value of the material for which the K electrons can be ejected (use
Moseley’s law)? What is the kinetic energy of the ejected electron for
Cu?
11. Given that the K-absorption edges for lead is 0.140 Å, and the minimum
voltage required for producing K lines in lead is 88.6 keV, determine the
ratio of h/e.
12. For Cu, determine the kinetic energy of the Auger electron for the transition
in which two vacancies are created in the L I shell in filling up a K-shell
vacancy (some simplifying assumptions may be required.)
13. Assuming that Na
+
and Cl
–
behave like hard balls or radii 1.0 Å and 1.8 Å
respectively (as far as repulsive forces are concerned), estimate the
dissociation energy for a NaCl molecule. The ionization potential of Na is
5.1 eV and the electron affinity for Cl is 3.8 eV.
14. For the HCl molecule, lines are found as v/c equal to 2944, 2926, 2908,
2866, 2844, 2821 cm
–1
. Determine the force constant for the vibrational
motion, and the distance of separation for the ions.
15. The rule of equal spacing is not strictly valid for the vibrational-rotational
band. Calculate the change in the energy if the moment of inertia in the
two vibrational states is different, say I 0 and I 1 . Estimate (I 1 – I 0 )/I 0 for
HCl for the states corresponding to the spectrum observed in Problem 14.