Transcript up11_educue_ch41 - University of Manchester

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
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
Q41.2
This illustration shows radial
probability distribution
functions for three hydrogenatom wave functions, plotted
versus r/a (r = distance from
the center of the atom, a =
0.0529 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
A41.2
This illustration shows radial
probability distribution
functions for three hydrogenatom wave functions, plotted
versus r/a (r = distance from
the center of the atom, a =
0.0529 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
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
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
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
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
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
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