d-Subshell Characteristics MCQ Questions and Answers
1. For a d-subshell, which complete set of magnetic quantum numbers is allowed, and what does it imply about the number of orbitals?
A. m_l = -2, -1, 0, +1, +2; five orbitals
B. m_l = -1, 0, +1; three orbitals
C. m_l = -3, -2, -1, 0, +1, +2, +3; seven orbitals
D. m_l = 0, +1, +2; three orbitals
Correct Answer:
m_l = -2, -1, 0, +1, +2; five orbitals
Explanation:
A d-subshell has azimuthal quantum number l = 2. Therefore, m_l can take the five values from -2 to +2, corresponding to five distinct orbitals.
2. An electron is described as belonging to a 4d subshell. Which statement about its quantum numbers is necessarily correct?
A. n = 4, l = 2, and m_l can have five possible values
B. n = 4, l = 3, and m_l can have seven possible values
C. n = 2, l = 4, and m_l can have nine possible values
D. n = 4, l = 1, and m_l can have three possible values
Correct Answer:
n = 4, l = 2, and m_l can have five possible values
Explanation:
The designation 4d fixes n = 4 and identifies the d-subshell, for which l = 2. Thus, five magnetic quantum numbers and five orbitals are possible.
3. What is the maximum number of electrons that can occupy a single d-subshell, and why?
A. 2, because a d-subshell contains one orbital
B. 6, because a d-subshell contains three orbitals
C. 10, because a d-subshell contains five orbitals, each holding two electrons
D. 14, because a d-subshell contains seven orbitals
Correct Answer:
10, because a d-subshell contains five orbitals, each holding two electrons
Explanation:
For a d-subshell, l = 2, giving 2l + 1 = 5 orbitals. Since each orbital can contain two electrons with opposite spins, the maximum occupancy is 10 electrons.
4. Which set contains only valid orbitals belonging to the same d-subshell?
A. 3d_xy, 3d_xz, 3d_z2, 3d_x2-y2, 3d_yz
B. 3d_xy, 3d_xz, 3p_z, 3d_x2-y2, 3d_yz
C. 4d_xy, 4d_xz, 3d_z2, 4d_x2-y2, 4d_yz
D. 3d_xy, 3d_xz, 3d_z2, 3f_xyz, 3d_yz
Correct Answer:
3d_xy, 3d_xz, 3d_z2, 3d_x2-y2, 3d_yz
Explanation:
The five orbitals of a d-subshell are conventionally represented as d_xy, d_xz, d_yz, d_x2-y2, and d_z2. All five listed orbitals in the correct option have the same principal shell and d-subshell designation.
5. For an electron in a 3d subshell, what is the number of angular nodes and radial nodes, respectively?
A. 2 and 0
B. 0 and 2
C. 2 and 1
D. 1 and 2
Correct Answer:
2 and 0
Explanation:
For a d-subshell, l = 2, so the number of angular nodes is 2. The number of radial nodes is n - l - 1 = 3 - 2 - 1 = 0.
6. Which statement correctly distinguishes the angular nodal characteristics of a d orbital from those of a p orbital?
A. A d orbital has two angular nodes, whereas a p orbital has one
B. A d orbital has one angular node, whereas a p orbital has two
C. Both d and p orbitals have no angular nodes
D. Both d and p orbitals always have two angular nodes
Correct Answer:
A d orbital has two angular nodes, whereas a p orbital has one
Explanation:
The number of angular nodes equals l. For a d orbital, l = 2, giving two angular nodes; for a p orbital, l = 1, giving one angular node.
7. Which statement about the five orbitals within an isolated d-subshell is most accurate?
A. They have different principal quantum numbers but identical orientations
B. They have the same n and l values but differ in their allowed m_l values and spatial orientations
C. They have different l values and therefore different subshell identities
D. They differ only in the number of electrons they can accommodate
Correct Answer:
They have the same n and l values but differ in their allowed m_l values and spatial orientations
Explanation:
Orbitals within one d-subshell share the same n and l values. Their different m_l values correspond to different orientations of the d-orbital wavefunctions in space.
8. Which pair of quantum-number descriptions represents two different orbitals of the same 5d subshell?
A. (n, l, m_l) = (5, 2, -1) and (5, 2, +2)
B. (n, l, m_l) = (5, 1, -1) and (5, 2, +2)
C. (n, l, m_l) = (4, 2, -1) and (5, 2, +2)
D. (n, l, m_l) = (5, 2, +3) and (5, 2, -2)
Correct Answer:
(n, l, m_l) = (5, 2, -1) and (5, 2, +2)
Explanation:
Two orbitals belong to the same 5d subshell when n = 5 and l = 2 for both, while their allowed m_l values are different. For a d-subshell, -2 ≤ m_l ≤ +2, so both -1 and +2 are valid.
9. A subshell contains exactly five orbitals and has two angular nodes in each orbital. Which identification is correct?
A. It is an s-subshell with l = 0
B. It is a p-subshell with l = 1
C. It is a d-subshell with l = 2
D. It is an f-subshell with l = 3
Correct Answer:
It is a d-subshell with l = 2
Explanation:
Two angular nodes indicate l = 2, which defines a d-subshell. The number of orbitals is 2l + 1 = 5, confirming the identification.
10. For a 4d orbital, which combination gives its total number of nodes, angular nodes, and radial nodes, respectively?
A. 4, 2, 2
B. 3, 2, 1
C. 3, 1, 2
D. 2, 2, 1
Correct Answer:
3, 2, 1
Explanation:
For a 4d orbital, n = 4 and l = 2. Total nodes equal n - 1 = 3, angular nodes equal l = 2, and radial nodes equal n - l - 1 = 1.
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