Q. In the context of atomic structure, what does the term 'isotope' refer to? (2021)
A.
Atoms with the same number of protons but different neutrons
B.
Atoms with different numbers of protons
C.
Atoms with the same mass number
D.
Atoms that are chemically identical
Show solution
Solution
Isotopes are defined as atoms that have the same number of protons but different numbers of neutrons.
Correct Answer: A — Atoms with the same number of protons but different neutrons
Learn More →
Q. In the context of atomic structure, what does the term 'quantum leap' refer to? (2022)
A.
Movement of electrons in a circular path
B.
Transition of an electron between energy levels
C.
Emission of light
D.
Absorption of energy
Show solution
Solution
A 'quantum leap' refers to the transition of an electron between discrete energy levels in an atom.
Correct Answer: B — Transition of an electron between energy levels
Learn More →
Q. In the hydrogen atom, which transition would emit the photon with the highest energy? (2019)
A.
n=2 to n=1
B.
n=3 to n=2
C.
n=4 to n=3
D.
n=5 to n=4
Show solution
Solution
The energy of the emitted photon is highest for the transition from n=2 to n=1, as it involves the largest energy difference.
Correct Answer: A — n=2 to n=1
Learn More →
Q. In the photoelectric effect, what happens to the kinetic energy of emitted electrons as the frequency of incident light increases? (2021)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
Show solution
Solution
According to the photoelectric effect, the kinetic energy of emitted electrons increases with the frequency of the incident light, provided the frequency is above the threshold frequency.
Correct Answer: A — Increases
Learn More →
Q. In the photoelectric effect, what happens to the kinetic energy of emitted electrons when the frequency of incident light is increased? (2021)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
Show solution
Solution
According to the photoelectric effect, the kinetic energy of emitted electrons increases with the frequency of the incident light, provided the frequency is above the threshold frequency.
Correct Answer: A — Increases
Learn More →
Q. In the photoelectric effect, what happens when the frequency of incident light is increased? (2020)
A.
More electrons are emitted
B.
Electrons are emitted with higher energy
C.
No electrons are emitted
D.
The current decreases
Show solution
Solution
Increasing the frequency of incident light increases the energy of emitted electrons, as per E = hf.
Correct Answer: B — Electrons are emitted with higher energy
Learn More →
Q. What is the atomic number of an element with 12 protons? (2020)
Show solution
Solution
The atomic number of an element is defined as the number of protons in its nucleus. Therefore, an element with 12 protons has an atomic number of 12.
Correct Answer: B — 12
Learn More →
Q. What is the energy of a photon emitted when an electron transitions from n=3 to n=2 in a hydrogen atom? (2019)
A.
1.89 eV
B.
3.40 eV
C.
10.20 eV
D.
12.09 eV
Show solution
Solution
The energy difference can be calculated using the formula E = 13.6 eV (1/n1² - 1/n2²). For n1=2 and n2=3, E = 13.6 eV (1/2² - 1/3²) = 1.89 eV.
Correct Answer: A — 1.89 eV
Learn More →
Q. What is the energy of a photon emitted when an electron transitions from n=4 to n=2 in a hydrogen atom? (2019)
A.
10.2 eV
B.
12.1 eV
C.
1.89 eV
D.
3.4 eV
Show solution
Solution
The energy difference can be calculated using the formula E = 13.6 eV (1/n1² - 1/n2²). For n1=2 and n2=4, E = 13.6(1/2² - 1/4²) = 10.2 eV.
Correct Answer: A — 10.2 eV
Learn More →
Q. What is the ground state electron configuration of an oxygen atom? (2023)
A.
1s² 2s² 2p⁴
B.
1s² 2s² 2p²
C.
1s² 2s² 2p⁶
D.
1s² 2s¹ 2p⁵
Show solution
Solution
Oxygen has 8 electrons, and its ground state electron configuration is 1s² 2s² 2p⁴.
Correct Answer: A — 1s² 2s² 2p⁴
Learn More →
Q. What is the ionization energy of an atom? (2023)
A.
Energy required to remove an electron
B.
Energy released when an electron is added
C.
Energy required to excite an electron
D.
Energy required to split the nucleus
Show solution
Solution
Ionization energy is defined as the energy required to remove an electron from an atom in its gaseous state.
Correct Answer: A — Energy required to remove an electron
Learn More →
Q. What is the ionization energy of hydrogen in eV? (2019)
A.
1.51 eV
B.
13.6 eV
C.
3.4 eV
D.
10.2 eV
Show solution
Solution
The ionization energy of hydrogen is 13.6 eV, which is the energy required to remove the electron from the ground state.
Correct Answer: B — 13.6 eV
Learn More →
Q. What is the main assumption of the quantum mechanical model of the atom? (2023)
A.
Electrons are in fixed orbits
B.
Electrons have wave-like properties
C.
Electrons are stationary
D.
Electrons have no mass
Show solution
Solution
The quantum mechanical model assumes that electrons exhibit both particle and wave-like properties.
Correct Answer: B — Electrons have wave-like properties
Learn More →
Q. What is the main idea behind the concept of quantization in atomic physics? (2023)
A.
Energy levels are continuous
B.
Energy levels are discrete
C.
Electrons can exist anywhere
D.
Atoms are indivisible
Show solution
Solution
Quantization in atomic physics means that energy levels in an atom are discrete, not continuous.
Correct Answer: B — Energy levels are discrete
Learn More →
Q. What is the main limitation of the Rutherford model of the atom? (2019)
A.
It does not explain the stability of atoms
B.
It does not account for neutrons
C.
It cannot explain spectral lines
D.
It does not include electrons
Show solution
Solution
The Rutherford model fails to explain why electrons do not spiral into the nucleus, thus not accounting for atomic stability.
Correct Answer: A — It does not explain the stability of atoms
Learn More →
Q. What is the main reason for the stability of the electron in an atom? (2019)
A.
Electrostatic attraction to the nucleus
B.
High energy levels
C.
Quantum tunneling
D.
Magnetic forces
Show solution
Solution
The stability of the electron in an atom is primarily due to the electrostatic attraction between the negatively charged electrons and the positively charged nucleus.
Correct Answer: A — Electrostatic attraction to the nucleus
Learn More →
Q. What is the maximum number of electrons that can occupy the n=3 energy level in an atom? (2021)
Show solution
Solution
The maximum number of electrons in an energy level is given by the formula 2n². For n=3, it is 2(3)² = 18.
Correct Answer: C — 18
Learn More →
Q. What is the maximum number of electrons that can occupy the n=4 energy level? (2021)
Show solution
Solution
The maximum number of electrons in an energy level is given by 2n^2. For n=4, it is 2(4^2) = 32.
Correct Answer: B — 18
Learn More →
Q. What is the principal quantum number for an electron in the third energy level? (2019)
Show solution
Solution
The principal quantum number (n) indicates the energy level; for the third energy level, n = 3.
Correct Answer: C — 3
Learn More →
Q. What is the significance of the Heisenberg Uncertainty Principle in atomic physics? (2023)
A.
It defines the position of an electron
B.
It states that energy levels are quantized
C.
It limits the precision of measuring position and momentum
D.
It explains the stability of the nucleus
Show solution
Solution
The Heisenberg Uncertainty Principle states that it is impossible to simultaneously know the exact position and momentum of a particle.
Correct Answer: C — It limits the precision of measuring position and momentum
Learn More →
Q. What is the significance of the Pauli Exclusion Principle in atomic structure? (2019)
A.
No two electrons can have the same set of quantum numbers.
B.
Electrons fill the lowest energy levels first.
C.
Electrons repel each other.
D.
Electrons can exist in any energy state.
Show solution
Solution
The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of quantum numbers.
Correct Answer: A — No two electrons can have the same set of quantum numbers.
Learn More →
Q. What is the wavelength of light emitted when an electron transitions from n=3 to n=1 in a hydrogen atom? (2020)
A.
102.6 nm
B.
656.3 nm
C.
486.1 nm
D.
434.0 nm
Show solution
Solution
Using the Rydberg formula, the wavelength for the transition from n=3 to n=1 can be calculated to be approximately 102.6 nm.
Correct Answer: A — 102.6 nm
Learn More →
Q. What is the wavelength of light emitted when an electron transitions from n=4 to n=2 in a hydrogen atom? (2020)
A.
486 nm
B.
656 nm
C.
434 nm
D.
410 nm
Show solution
Solution
Using the Rydberg formula, the wavelength for the transition from n=4 to n=2 can be calculated to be approximately 486 nm.
Correct Answer: A — 486 nm
Learn More →
Q. Which of the following describes the concept of quantization in atomic physics? (2023)
A.
Energy levels are continuous.
B.
Energy levels are discrete.
C.
Electrons can exist anywhere.
D.
All of the above.
Show solution
Solution
Quantization means that energy levels in an atom are discrete, not continuous.
Correct Answer: B — Energy levels are discrete.
Learn More →
Q. Which of the following describes the emission spectrum of hydrogen? (2023)
A.
Continuous spectrum
B.
Line spectrum
C.
Absorption spectrum
D.
Black body spectrum
Show solution
Solution
The emission spectrum of hydrogen is a line spectrum, consisting of discrete lines corresponding to specific wavelengths of light emitted by electrons transitioning between energy levels.
Correct Answer: B — Line spectrum
Learn More →
Q. Which of the following quantum numbers describes the shape of an atomic orbital? (2022)
A.
Principal quantum number
B.
Azimuthal quantum number
C.
Magnetic quantum number
D.
Spin quantum number
Show solution
Solution
The azimuthal quantum number (l) describes the shape of the atomic orbital.
Correct Answer: B — Azimuthal quantum number
Learn More →
Q. Which of the following transitions in a hydrogen atom will emit the highest energy photon? (2019)
A.
n=2 to n=1
B.
n=3 to n=2
C.
n=4 to n=3
D.
n=5 to n=4
Show solution
Solution
The energy of the emitted photon is highest for the transition from n=2 to n=1, as it involves the largest difference in energy levels.
Correct Answer: A — n=2 to n=1
Learn More →
Q. Which particle is responsible for the chemical properties of an atom? (2023)
A.
Neutrons
B.
Protons
C.
Electrons
D.
Nucleons
Show solution
Solution
Electrons, particularly those in the outer shell, determine the chemical properties of an atom.
Correct Answer: C — Electrons
Learn More →
Showing 1 to 28 of 28 (1 Pages)