1. Q41.1
This illustration shows the possible orientations of the angular momentum vector in a hydrogen atom state with l = 2.
This illustration tells us that for a given value of Lz,
1. the angular momentum vector can point in any direction tangent to the cone for that value of Lz
2. the electron orbits along one of the red circles, so the orbit may or may not have the nucleus at its center
3. both 1. and 2. are true
4. neither 1. nor 2. is true

2. A41.1
This illustration shows the possible orientations of the angular momentum vector in a hydrogen atom state with l = 2.
This illustration tells us that for a given value of Lz,
1. the angular momentum vector can point in any direction tangent to the cone for that value of Lz
2. the electron orbits along one of the red circles, so the orbit may or may not have the nucleus at its center
3. both 1. and 2. are true
4. neither 1. nor 2. is true

3. Q41.2
This illustration shows radial probability distribution functions for three hydrogen-atom wave functions, plotted versus r/a (r = distance from the center of the atom, a = nm).
Which statement is correct?
1. a hydrogen electron in a 4p state is always farther from the center of the atom than is a hydrogen electron in a 2p state
2. a hydrogen electron in a 2p state is never found at the precise center of the atom
3. a 3p state has 3 units of orbital angular momentum
4. none of the above is true

4. A41.2
This illustration shows radial probability distribution functions for three hydrogen-atom wave functions, plotted versus r/a (r = distance from the center of the atom, a = nm).
Which statement is correct?
1. a hydrogen electron in a 4p state is always farther from the center of the atom than is a hydrogen electron in a 2p state
2. a hydrogen electron in a 2p state is never found at the precise center of the atom
3. a 3p state has 3 units of orbital angular momentum
4. none of the above is true

5. Q41.3
If a sample of gas atoms is placed in a strong, uniform magnetic field, the spectrum of the atoms changes. Why is this?
1. electrons have magnetic moments due to their spin and their orbital motion
2. the nucleus is positively charged and the electrons are negatively charged, so they are pushed in opposite directions by a magnetic field
3. electrons are drawn into regions of strong magnetic field
4. electrons are repelled from regions of strong magnetic field
5. none of the above

6. A41.3
If a sample of gas atoms is placed in a strong, uniform magnetic field, the spectrum of the atoms changes. Why is this?
1. electrons have magnetic moments due to their spin and their orbital motion
2. the nucleus is positively charged and the electrons are negatively charged, so they are pushed in opposite directions by a magnetic field
3. electrons are drawn into regions of strong magnetic field
4. electrons are repelled from regions of strong magnetic field
5. none of the above

7. Q41.4
Potassium has 19 electrons. It is relatively easy to remove one electron, but substantially more difficult to then remove a second electron. Why is this?
1. the second electron feels a stronger attraction to the other electrons than did the first electron that was removed
2. when the first electron is removed, the other electrons readjust their orbits so that they are closer to the nucleus
3. the first electron to be removed was screened from more of the charge on the nucleus than is the second electron
4. all of the above
5. none of the above

8. A41.4
Potassium has 19 electrons. It is relatively easy to remove one electron, but substantially more difficult to then remove a second electron. Why is this?
1. the second electron feels a stronger attraction to the other electrons than did the first electron that was removed
2. when the first electron is removed, the other electrons readjust their orbits so that they are closer to the nucleus
3. the first electron to be removed was screened from more of the charge on the nucleus than is the second electron
4. all of the above
5. none of the above

9. Q41.5
Ordinary hydrogen has one electron and one proton. It requires 10.2 eV of energy to move an electron from the innermost (K) shell in hydrogen into the next (L) shell.
The most common form of uranium has 92 electrons, 92 protons, and 146 neutrons. The energy required to move an electron from the K shell to the L shell of this form of uranium is
1. (91)(10.2 eV)
2. (92)(10.2 eV)
3. (91)2(10.2 eV)
4. (92)2(10.2 eV)
5. none of the above

10. A41.5
Ordinary hydrogen has one electron and one proton. It requires 10.2 eV of energy to take an electron from the innermost (K) shell in hydrogen and move it into the next (L) shell.
The most common form of uranium has 92 electrons, 92 protons, and 146 neutrons. The energy required to move an electron from the K shell to the L shell of this form of uranium is
1. (91)(10.2 eV)
2. (92)(10.2 eV)
3. (91)2(10.2 eV)
4. (92)2(10.2 eV)
5. none of the above