Q. What is the principal quantum number of the outermost electron in potassium (K)?
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Solution
Potassium has the electronic configuration [Ar] 4s1, so the principal quantum number of the outermost electron is 4.
Correct Answer:
A
— 3
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Q. What is the principal quantum number of the valence electrons in chlorine?
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Solution
Chlorine has an atomic number of 17, and its valence electrons are in the n=3 shell.
Correct Answer:
B
— 3
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Q. What is the relationship between the principal quantum number (n) and the energy of an electron in a hydrogen atom?
A.
Energy increases with increasing n
B.
Energy decreases with increasing n
C.
Energy is independent of n
D.
Energy is maximum at n=1
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Solution
In a hydrogen atom, the energy of an electron increases with increasing principal quantum number (n).
Correct Answer:
A
— Energy increases with increasing n
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Q. What is the shape of the d orbitals?
A.
Spherical
B.
Dumbbell
C.
Double dumbbell
D.
Linear
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Solution
The d orbitals have a double dumbbell shape.
Correct Answer:
C
— Double dumbbell
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Q. What is the shape of the p-orbital?
A.
Spherical
B.
Dumbbell
C.
Double dumbbell
D.
Linear
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Solution
The p-orbital has a dumbbell shape.
Correct Answer:
B
— Dumbbell
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Q. What is the spin quantum number (m_s) for an electron in an orbital?
A.
0
B.
+1/2
C.
-1/2
D.
1
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Solution
The spin quantum number can be +1/2 or -1/2 for an electron in an orbital.
Correct Answer:
B
— +1/2
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Q. What is the spin quantum number (m_s) for an electron with a clockwise spin?
A.
-1/2
B.
0
C.
+1/2
D.
1
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Solution
The spin quantum number (m_s) is +1/2 for an electron with clockwise spin.
Correct Answer:
C
— +1/2
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Q. What is the spin quantum number (m_s) for an electron?
A.
0
B.
+1/2
C.
-1/2
D.
Both +1/2 and -1/2
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Solution
The spin quantum number (m_s) can be +1/2 or -1/2 for an electron.
Correct Answer:
D
— Both +1/2 and -1/2
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Q. What is the total number of electrons in the electronic configuration [Kr] 5s2 4d10 5p5?
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Solution
The total number of electrons is 36 (from Kr) + 2 (from 5s2) + 10 (from 4d10) + 5 (from 5p5) = 53.
Correct Answer:
D
— 53
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Q. What is the total number of orbitals in the n=2 shell?
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Solution
The n=2 shell has 4 orbitals: 1s and 3p orbitals.
Correct Answer:
B
— 4
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Q. What is the total number of orbitals in the n=3 energy level?
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Solution
The total number of orbitals in the n=3 level is given by n^2 = 3^2 = 9.
Correct Answer:
B
— 6
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Q. What is the total number of orbitals in the n=4 shell?
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Solution
The total number of orbitals in a shell is given by n^2. For n=4, it is 4^2 = 16.
Correct Answer:
C
— 16
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Q. What is the total number of quantum numbers required to completely describe an electron in an atom?
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Solution
Four quantum numbers (n, l, m_l, s) are required to completely describe an electron in an atom.
Correct Answer:
C
— 4
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Q. What is the value of l for a d orbital?
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Solution
For d orbitals, the azimuthal quantum number l is equal to 2.
Correct Answer:
C
— 2
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Q. What is the value of the principal quantum number (n) for an electron in the 4f subshell?
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Solution
The principal quantum number n for the f subshell is 4.
Correct Answer:
B
— 4
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Q. What is the value of the principal quantum number (n) for an electron in the 4s orbital?
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Solution
The principal quantum number (n) indicates the energy level of the electron. For 4s, n=4.
Correct Answer:
D
— 4
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Q. What is the value of the principal quantum number (n) for an electron in the ground state of a hydrogen atom?
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Solution
In the ground state, the electron is in the first energy level, which corresponds to n=1.
Correct Answer:
B
— 1
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Q. What is the value of the principal quantum number (n) for the outermost electron in potassium (K)?
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Solution
Potassium has the electronic configuration [Ar] 4s1, so the outermost electron is in n=4.
Correct Answer:
B
— 4
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Q. What is the value of the principal quantum number (n) for the outermost electrons in a sodium atom?
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Solution
Sodium has an atomic number of 11, and its electron configuration is 1s² 2s² 2p⁶ 3s¹. The outermost electrons are in n=3.
Correct Answer:
C
— 3
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Q. What is the value of the principal quantum number (n) for the outermost electron in a potassium atom?
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Solution
Potassium (K) has an atomic number of 19, and its electron configuration ends in 4s, so the outermost electron has n=4.
Correct Answer:
C
— 3
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Q. What is the value of the principal quantum number for an electron in the ground state of a hydrogen atom?
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Solution
The ground state of hydrogen corresponds to n=1.
Correct Answer:
A
— 1
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Q. What is the value of the principal quantum number for the outermost electrons in potassium (K)?
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Solution
Potassium has an atomic number of 19, and its outermost electrons are in the n=4 shell.
Correct Answer:
D
— 4
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Q. What is the value of the principal quantum number for the outermost electrons in a sodium atom?
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Solution
Sodium has an atomic number of 11, and its outermost electrons are in the n=3 shell.
Correct Answer:
C
— 3
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Q. Which element has the electronic configuration 1s2 2s2 2p6 3s2 3p1?
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Solution
The element with the configuration 1s2 2s2 2p6 3s2 3p1 is Aluminum (Al).
Correct Answer:
A
— Al
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Q. Which element has the electronic configuration 1s2 2s2 2p6 3s2 3p6 4s2?
A.
Arsenic
B.
Calcium
C.
Krypton
D.
Titanium
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Solution
The configuration corresponds to Krypton (Kr), which has 36 electrons.
Correct Answer:
C
— Krypton
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Q. Which of the following configurations is incorrect?
A.
1s2 2s2 2p6 3s2
B.
1s2 2s2 2p6 3s2 3p6
C.
1s2 2s2 2p6 3s2 3p1
D.
1s2 2s2 2p6 3s2 3p5
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Solution
The configuration 1s2 2s2 2p6 3s2 3p6 is incorrect as it exceeds the maximum number of electrons in the 3rd shell.
Correct Answer:
B
— 1s2 2s2 2p6 3s2 3p6
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Q. Which of the following configurations represents a noble gas?
A.
1s2 2s2 2p6
B.
1s2 2s2 2p5
C.
1s2 2s2 2p4
D.
1s2 2s2 2p3
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Solution
The configuration 1s2 2s2 2p6 corresponds to Neon, a noble gas.
Correct Answer:
A
— 1s2 2s2 2p6
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Q. Which of the following configurations represents a transition metal?
A.
[Ar] 4s2 3d10
B.
[Ne] 3s2 3p6
C.
[Kr] 5s2 4d5
D.
[Xe] 6s2
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Solution
The configuration [Kr] 5s2 4d5 represents Molybdenum (Mo), a transition metal.
Correct Answer:
C
— [Kr] 5s2 4d5
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Q. Which of the following elements has a half-filled p subshell?
A.
Boron
B.
Carbon
C.
Nitrogen
D.
Oxygen
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Solution
Nitrogen has the electronic configuration 1s2 2s2 2p3, which means it has a half-filled p subshell.
Correct Answer:
C
— Nitrogen
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Q. Which of the following elements has an incomplete d subshell?
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Solution
Chromium (Cr) has an electronic configuration of [Ar] 4s1 3d5, which means it has an incomplete d subshell.
Correct Answer:
D
— Cr
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Showing 61 to 90 of 141 (5 Pages)
Atomic Structure MCQ & Objective Questions
Understanding atomic structure is crucial for students preparing for school exams and competitive tests. This topic lays the foundation for various concepts in chemistry and physics, making it essential for scoring well. Practicing MCQs and objective questions on atomic structure not only enhances your knowledge but also boosts your confidence in tackling important questions during exams.
What You Will Practise Here
Basic concepts of atomic structure, including atoms, molecules, and ions.
Key theories such as Dalton's atomic theory and the Bohr model.
Understanding subatomic particles: protons, neutrons, and electrons.
Atomic number, mass number, and isotopes.
Electron configuration and its significance in chemical bonding.
Quantum numbers and their role in defining electron orbits.
Important diagrams illustrating atomic models and structures.
Exam Relevance
The topic of atomic structure frequently appears in CBSE, State Boards, NEET, and JEE exams. Students can expect questions that assess their understanding of atomic models, the behavior of subatomic particles, and electron configurations. Common question patterns include multiple-choice questions that require students to identify correct statements or solve problems related to atomic structure.
Common Mistakes Students Make
Confusing atomic number with mass number.
Misunderstanding the concept of isotopes and their applications.
Errors in determining electron configurations for different elements.
Overlooking the significance of quantum numbers in electron arrangement.
Failing to relate atomic structure concepts to chemical properties.
FAQs
Question: What is atomic structure?Answer: Atomic structure refers to the arrangement of protons, neutrons, and electrons in an atom, which determines its properties and behavior.
Question: How can I prepare effectively for atomic structure questions?Answer: Regular practice of MCQs and objective questions, along with a thorough understanding of key concepts, will help you prepare effectively.
Now is the time to enhance your understanding of atomic structure! Dive into our practice MCQs and test your knowledge to excel in your exams.