Class 11 Chemistry MCQ – Structure of Atom

MCQs on Class 11 Structure of Atom: CBSE Class 11 students should be familiar with the new exam pattern where 50% of the questions are in MCQ format. The board has increased the importance of multiple-choice questions as they test students’ problem-solving and critical thinking abilities. It’s important for students to practice different types of questions to understand what might appear in the exam. In this article, you will find MCQs for CBSE Class 11 Chemistry Chapter 2, Structure of Atom. The questions are created by subject experts and cover key concepts from the chapter. These MCQs are perfect for preparing for the 2024-25 exams. You can read and download all the questions and answers in PDF from the link provided at the end of the article.

Class 11 Structure of Atom MCQs – Question with Answers

Which of the following is true for Rutherford’s model of an atom?
a) Electrons revolve in fixed orbits
b) The nucleus is positively charged
c) Electrons are stationary
d) Electrons have no energy

Answer: b) The nucleus is positively charged
Who proposed the idea of quantized energy levels?
a) Rutherford
b) Bohr
c) Thomson
d) Heisenberg

Answer: b) Bohr
The mass number of an atom is the sum of the number of?
a) Electrons and protons
b) Protons and neutrons
c) Neutrons and electrons
d) Protons and ions

Answer: b) Protons and neutrons
The discovery of the electron was made by?
a) Bohr
b) Rutherford
c) J.J. Thomson
d) Chadwick

Answer: c) J.J. Thomson
What is the charge of a proton?
a) Positive
b) Negative
c) Neutral
d) Undefined

Answer: a) Positive
The number of protons in an atom is also called its?
a) Atomic number
b) Mass number
c) Neutron number
d) Electron number

Answer: a) Atomic number
Which subatomic particle was discovered using the gold foil experiment?
a) Electron
b) Neutron
c) Proton
d) Nucleus

Answer: c) Proton
In Bohr’s model, the electrons move in?
a) Random orbits
b) Fixed orbits
c) Free paths
d) None of the above

Answer: b) Fixed orbits
The frequency of electromagnetic radiation is inversely proportional to its?
a) Wavelength
b) Energy
c) Speed
d) Charge

Answer: a) Wavelength
Which of the following has the smallest wavelength?
a) Radio waves
b) Microwaves
c) X-rays
d) Ultraviolet rays

Answer: c) X-rays
The uncertainty principle was formulated by?
a) Bohr
b) Heisenberg
c) Rutherford
d) Thomson

Answer: b) Heisenberg
What does the principal quantum number (n) represent?
a) Shape of the orbital
b) Energy level of an electron
c) Orientation of the orbital
d) Spin of the electron

Answer: b) Energy level of an electron
What is the maximum number of electrons that can occupy the second energy level?
a) 2
b) 8
c) 18
d) 32

Answer: b) 8
Which of the following elements has its electrons filling the 3d orbital first?
a) Sodium
b) Magnesium
c) Copper
d) Neon

Answer: c) Copper
Which of the following quantum numbers is associated with the shape of an orbital?
a) Principal quantum number (n)
b) Azimuthal quantum number (l)
c) Magnetic quantum number (m)
d) Spin quantum number (s)

Answer: b) Azimuthal quantum number (l)
Which atomic model introduced the concept of quantized energy levels?
a) Rutherford model
b) Bohr model
c) Thomson model
d) Quantum mechanical model

Answer: b) Bohr model
The number of orbitals in the 3p sublevel is?
a) 1
b) 2
c) 3
d) 6

Answer: c) 3
Which of the following particles is electrically neutral?
a) Proton
b) Electron
c) Neutron
d) Positron

Answer: c) Neutron
The electron cloud model is based on which theory?
a) Bohr’s theory
b) Wave mechanics
c) Rutherford’s theory
d) Quantum theory

Answer: b) Wave mechanics
What is the charge of an electron?
a) Positive
b) Negative
c) Neutral
d) Undefined

Answer: b) Negative
Which quantum number determines the orientation of an orbital?
a) Principal quantum number
b) Azimuthal quantum number
c) Magnetic quantum number
d) Spin quantum number

Answer: c) Magnetic quantum number
Which of the following has a negative charge?
a) Proton
b) Neutron
c) Electron
d) Positron

Answer: c) Electron
What is the maximum number of electrons that can occupy the third energy level?
a) 8
b) 18
c) 32
d) 50

Answer: b) 18
The energy of an electron in an atom is quantized according to?
a) Bohr’s model
b) Rutherford’s model
c) De Broglie’s principle
d) Heisenberg’s principle

Answer: a) Bohr’s model
What does the angular momentum quantum number (l) describe?
a) Energy of the electron
b) Orientation of the orbital
c) Shape of the orbital
d) Spin of the electron

Answer: c) Shape of the orbital
The atomic number of an element represents the number of?
a) Protons
b) Neutrons
c) Electrons
d) Both protons and neutrons

Answer: a) Protons
Which of the following best describes an isotope?
a) Same atomic number, different mass number
b) Different atomic number, same mass number
c) Same number of protons and neutrons
d) Same number of protons and electrons

Answer: a) Same atomic number, different mass number
The emission spectrum of hydrogen can be explained by?
a) Rutherford model
b) Thomson model
c) Bohr model
d) Quantum mechanical model

Answer: c) Bohr model
What does the magnetic quantum number (m) specify?
a) Energy of the electron
b) Orientation of the orbital
c) Shape of the orbital
d) Spin of the electron

Answer: b) Orientation of the orbital
The wave nature of electrons was explained by?
a) De Broglie
b) Rutherford
c) Planck
d) Heisenberg

Answer: a) De Broglie
The number of electrons in the second energy level of an atom is?
a) 2
b) 8
c) 18
d) 32

Answer: b) 8
Which of the following is not a possible value for the magnetic quantum number (m) in a 3d orbital?
a) -1
b) 0
c) 1
d) 2

Answer: d) 2
What is the shape of the s orbital?
a) Spherical
b) Dumbbell
c) Circular
d) None of the above

Answer: a) Spherical
Which principle states that no two electrons in an atom can have the same set of quantum numbers?
a) Pauli exclusion principle
b) Hund’s rule
c) Aufbau principle
d) Heisenberg uncertainty principle

Answer: a) Pauli exclusion principle
The frequency of a photon is directly proportional to its?
a) Wavelength
b) Energy
c) Speed
d) Intensity

Answer: b) Energy
Which of the following has the highest energy?
a) Red light
b) Violet light
c) Infrared rays
d) X-rays

Answer: d) X-rays
The formula for calculating the energy of an electron in the nth orbit is given by?
a) E = -2.18 × 10^-18 (1/n^2)
b) E = -13.6 × 10^-19 (1/n^2)
c) E = -13.6 × 10^-18 (1/n^2)
d) E = -2.18 × 10^-19 (1/n^2)

Answer: b) E = -13.6 × 10^-19 (1/n^2)
The concept of quantization of energy was introduced by?
a) Max Planck
b) Albert Einstein
c) Louis de Broglie
d) Niels Bohr

Answer: a) Max Planck
Which of the following quantum numbers is not required to specify an electron in an atom?
a) Principal quantum number
b) Azimuthal quantum number
c) Magnetic quantum number
d) Mass number

Answer: d) Mass number
Which of the following is not a valid orbital?
a) 3d
b) 2s
c) 1p
d) 4p

Answer: c) 1p