chemistry : class11 Subshell Filling Order : Concept of subshells : Structure of Atom MCQ Questions and Answers
Practice important
Subshell Filling Order
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. According to the subshell filling order based on the Aufbau principle, which sequence is arranged in the correct increasing order of energy?
A.
3d < 4s < 4p
B.
4s < 3d < 4p
C.
4p < 3d < 4s
D.
3d < 4p < 4s
Correct Answer:
4s < 3d < 4p
Explanation:
The accepted filling order is 4s, followed by 3d, and then 4p. Although 3d has a lower principal shell number than 4s, the 4s subshell is filled first because subshell energies follow the n+l rule.
2. Which subshell is the fifth subshell to be filled in the ground-state Aufbau sequence?
A.
3s
B.
3p
C.
4s
D.
2p
Correct Answer:
3p
Explanation:
The filling sequence begins 1s, 2s, 2p, 3s, and 3p. Therefore, 3p is the fifth subshell in the subshell filling order.
3. Which pair of subshells has the same value of n+l, and which one is filled first according to the n+l rule?
A.
3d and 4p; 4p is filled first
B.
4p and 5s; 4p is filled first
C.
4s and 3d; 3d is filled first
D.
5s and 4d; 4d is filled first
Correct Answer:
4p and 5s; 4p is filled first
Explanation:
For 4p, n+l = 4+1 = 5, and for 5s, n+l = 5+0 = 5. When n+l values are equal, the subshell with the lower n value is filled first, so 4p precedes 5s.
4. Which subshell is filled immediately after 6s in the conventional Aufbau sequence?
A.
5d
B.
6p
C.
4f
D.
5f
Correct Answer:
4f
Explanation:
The relevant portion of the filling sequence is 5p, 6s, 4f, 5d, 6p. Hence, 4f is filled immediately after 6s.
5. Which proposed sequence contains the first incorrect step in the subshell filling order?
A.
1s, 2s, 2p, 3s
B.
3p, 4s, 3d, 4p
C.
5s, 4d, 5p, 6s
D.
6s, 5d, 4f, 6p
Correct Answer:
6s, 5d, 4f, 6p
Explanation:
After 6s, the correct order is 4f, then 5d, and then 6p. Therefore, placing 5d before 4f violates the subshell filling order.
6. In the complete Aufbau sequence, which position is occupied by the 7p subshell when subshells are counted individually?
A.
17th
B.
18th
C.
19th
D.
20th
Correct Answer:
19th
Explanation:
The sequence reaches 7p as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p. Thus, 7p is the 19th subshell filled.
7. Among the subshells having principal quantum number n = 5, which one is encountered first in the Aufbau filling order?
A.
5p
B.
5d
C.
5s
D.
5f
Correct Answer:
5s
Explanation:
The 5s subshell has the lowest n+l value among the listed n = 5 subshells: 5s has 5, 5p has 6, 5d has 7, and 5f has 8. Therefore, 5s is filled first.
8. Which subshell is filled immediately before 6s in the standard subshell filling order?
A.
5p
B.
4d
C.
5d
D.
6p
Correct Answer:
5p
Explanation:
The relevant order is 4d, 5p, 6s, 4f. Hence, 5p is the subshell filled immediately before 6s.
9. Which ordering correctly represents the relative filling sequence of the 5s, 4d, and 5p subshells?
A.
4d < 5s < 5p
B.
5p < 4d < 5s
C.
5s < 4d < 5p
D.
5s < 5p < 4d
Correct Answer:
5s < 4d < 5p
Explanation:
For 5s, 4d, and 5p, the n+l values are 5, 6, and 6 respectively. Between 4d and 5p, the lower n value of 4d gives it priority, resulting in 5s < 4d < 5p.
10. The 5f and 6d subshells have equal n+l values. Which one is filled first, and why?
A.
6d, because its principal quantum number is larger
B.
5f, because its principal quantum number is smaller
C.
6d, because d subshells always fill before f subshells
D.
5f, because f subshells always fill before d subshells
Correct Answer:
5f, because its principal quantum number is smaller
Explanation:
For both 5f and 6d, n+l = 8. When n+l values are equal, the subshell with the smaller principal quantum number is filled first; therefore, 5f precedes 6d.
Short Questions and Answers
Practice short questions and answers related to
Subshell Filling Order
.
Short questions are currently unavailable for this page.