Atoms: Rutherford's Atom Model mcq with answers
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1. According to Rutherford’s alpha particle scattering experiment, the positively charged particles are:
A. Concentrated at the nucleus of an atom
B. Uniformly distributed throughout the atom
C. Scattered in the atom’s orbitals
D. Distributed across the atom’s periphery
The correct answer is A. Concentrated at the nucleus of an atom.
Explanation:
Rutherford’s experiment demonstrated that most of the alpha particles passed through the gold foil without deflection, indicating that atoms are mostly empty space. A small fraction of particles deflected back, which suggested that the positive charge and most of the mass of the atom are concentrated in a tiny region called the nucleus.
Conclusion:
The positively charged particles (protons) are concentrated at the nucleus of an atom.
Explanation:
Rutherford’s experiment demonstrated that most of the alpha particles passed through the gold foil without deflection, indicating that atoms are mostly empty space. A small fraction of particles deflected back, which suggested that the positive charge and most of the mass of the atom are concentrated in a tiny region called the nucleus.
Conclusion:
The positively charged particles (protons) are concentrated at the nucleus of an atom.
2. What did Rutherford’s gold foil experiment prove about the structure of an atom?
A. Atoms are solid spheres
B. Atoms have a small, dense nucleus
C. Atoms have a uniformly distributed charge
D. Electrons are stationary within the atom
The correct answer is A. Atoms have a small, dense nucleus.
Explanation:
Rutherford’s gold foil experiment showed that a majority of alpha particles passed through the foil with no deflection, but a few were deflected at large angles. This indicated the presence of a small, dense, positively charged nucleus at the center of the atom, surrounded by empty space.
Conclusion:
The experiment confirmed that atoms have a small, dense nucleus.
Explanation:
Rutherford’s gold foil experiment showed that a majority of alpha particles passed through the foil with no deflection, but a few were deflected at large angles. This indicated the presence of a small, dense, positively charged nucleus at the center of the atom, surrounded by empty space.
Conclusion:
The experiment confirmed that atoms have a small, dense nucleus.
3. Why do most of the alpha particles in Rutherford’s experiment pass through the gold foil undeflected?
The correct answer is A. Atoms are mostly empty space.
Explanation:
Rutherford’s gold foil experiment demonstrated that the majority of alpha particles passed through the foil without any deflection, indicating that atoms are mostly empty space with a small, dense nucleus causing occasional deflections.
Conclusion:
The experiment revealed that atoms consist mostly of empty space.
Explanation:
Rutherford’s gold foil experiment demonstrated that the majority of alpha particles passed through the foil without any deflection, indicating that atoms are mostly empty space with a small, dense nucleus causing occasional deflections.
Conclusion:
The experiment revealed that atoms consist mostly of empty space.
4. What would happen if the nucleus of an atom were not dense?
A. Atoms would have no charge distribution
B. Alpha particles would pass straight through without deflection
C. Electrons would collapse into the nucleus
D. Alpha particles would be deflected uniformly
The correct answer is A. Alpha particles would pass straight through without deflection.
Explanation:
The large deflections of alpha particles observed in Rutherford’s experiment occur due to the dense, positively charged nucleus. Without this density, there would be no significant deflection, and the alpha particles would pass straight through.
Conclusion:
The density of the nucleus is crucial for causing the observed deflections in Rutherford’s experiment.
Explanation:
The large deflections of alpha particles observed in Rutherford’s experiment occur due to the dense, positively charged nucleus. Without this density, there would be no significant deflection, and the alpha particles would pass straight through.
Conclusion:
The density of the nucleus is crucial for causing the observed deflections in Rutherford’s experiment.
5. In Rutherford’s model of the atom, the electrons:
A. Revolve around the nucleus in defined orbits
B. Are embedded within the nucleus
C. Move randomly inside the atom
D. Are stationary in fixed positions
The correct answer is A. Revolve around the nucleus in defined orbits.
Explanation:
According to Rutherford’s atomic model, electrons revolve around the dense, positively charged nucleus in well-defined orbits, much like planets around the sun. This motion prevents them from collapsing into the nucleus due to electrostatic attraction.
Conclusion:
Rutherford’s model described electrons as revolving in orbits around the nucleus.
Explanation:
According to Rutherford’s atomic model, electrons revolve around the dense, positively charged nucleus in well-defined orbits, much like planets around the sun. This motion prevents them from collapsing into the nucleus due to electrostatic attraction.
Conclusion:
Rutherford’s model described electrons as revolving in orbits around the nucleus.
6. In Rutherford’s alpha scattering experiment, a few alpha particles were deflected backward because:
A. They collided with the dense nucleus
B. They interacted with electrons
C. They passed through empty space
D. They were repelled by other alpha particles
The correct answer is A. They collided with the dense nucleus.
Explanation:
In Rutherford’s experiment, most alpha particles passed straight through the gold foil, but a few were deflected at large angles or even backward. This occurs when they come close to or collide with the dense, positively charged nucleus.
Conclusion:
The backward deflection of alpha particles indicated the presence of a dense nucleus in the atom.
Explanation:
In Rutherford’s experiment, most alpha particles passed straight through the gold foil, but a few were deflected at large angles or even backward. This occurs when they come close to or collide with the dense, positively charged nucleus.
Conclusion:
The backward deflection of alpha particles indicated the presence of a dense nucleus in the atom.
7. Which observation from Rutherford’s experiment contradicted the Thomson model of the atom?
A. Alpha particles were deflected at large angles
B. Alpha particles passed through the foil
C. Atoms emitted light upon collision
D. Electrons moved in orbits
The correct answer is A. Alpha particles were deflected at large angles.
Explanation:
According to Thomson’s model, the positive charge in an atom was thought to be uniformly distributed. Rutherford’s observation of large-angle deflections contradicted this, proving the existence of a concentrated nucleus.
Conclusion:
The deflections observed in Rutherford’s experiment provided evidence against the Thomson model.
Explanation:
According to Thomson’s model, the positive charge in an atom was thought to be uniformly distributed. Rutherford’s observation of large-angle deflections contradicted this, proving the existence of a concentrated nucleus.
Conclusion:
The deflections observed in Rutherford’s experiment provided evidence against the Thomson model.
8. Rutherford’s gold foil experiment showed that:
A. Alpha particles are negatively charged
B. Atoms are indivisible
C. Electrons are embedded in a positive sphere
D. Atoms have a dense, positively charged nucleus
The correct answer is A. Atoms have a dense, positively charged nucleus.
Explanation:
Rutherford’s experiment demonstrated that most of the alpha particles passed through the gold foil, but some were deflected at large angles. This observation led to the conclusion that atoms have a dense, positively charged nucleus at their center.
Conclusion:
The experiment revolutionized the understanding of atomic structure, proving the existence of a nucleus.
Explanation:
Rutherford’s experiment demonstrated that most of the alpha particles passed through the gold foil, but some were deflected at large angles. This observation led to the conclusion that atoms have a dense, positively charged nucleus at their center.
Conclusion:
The experiment revolutionized the understanding of atomic structure, proving the existence of a nucleus.
9. Which subatomic particle did Rutherford’s experiment most effectively discover?
C. The nucleus
A. The neutron
B. The electron
D. The proton
The correct answer is C. The nucleus.
Explanation:
Rutherford’s gold foil experiment led to the discovery of the nucleus. Most of the alpha particles passed through the atom, but a small number were deflected, indicating the presence of a dense positive core.
Explanation:
Rutherford’s gold foil experiment led to the discovery of the nucleus. Most of the alpha particles passed through the atom, but a small number were deflected, indicating the presence of a dense positive core.
10. What did Rutherford’s gold foil experiment mainly demonstrate?
A. Most of the atom is empty space
B. The presence of electrons
C. The structure of the atom was uniform
D. The atom was mostly solid
The correct answer is A. Most of the atom is empty space.
Explanation:
Rutherford’s experiment demonstrated that while most of the atom is empty space, the small dense core (nucleus) is where positive charge and most of the mass are concentrated.
Explanation:
Rutherford’s experiment demonstrated that while most of the atom is empty space, the small dense core (nucleus) is where positive charge and most of the mass are concentrated.
11. What was the conclusion of Rutherford’s experiment regarding the nucleus?
A. The atom is mostly a solid mass
B. Electrons are randomly distributed
C. The atom is mostly filled with electrons
D. The atom has a dense, positively charged nucleus
The correct answer is C. The atom has a dense, positively charged nucleus.
Explanation:
Rutherford concluded that the atom consists of a small, dense, positively charged nucleus with electrons surrounding it in mostly empty space.
Explanation:
Rutherford concluded that the atom consists of a small, dense, positively charged nucleus with electrons surrounding it in mostly empty space.
12. What major aspect of atomic theory did Rutherford’s model fail to explain?
B. The stability of the atom
A. The size of the nucleus
C. The arrangement of electrons
D. The presence of neutrons
The correct answer is B. The stability of the atom.
Explanation:
Rutherford’s model did not explain why electrons in orbit do not spiral into the nucleus due to electromagnetic attraction, a question addressed by the Bohr model.
Explanation:
Rutherford’s model did not explain why electrons in orbit do not spiral into the nucleus due to electromagnetic attraction, a question addressed by the Bohr model.
13. What key concept did Niels Bohr add to Rutherford’s atomic model?
A. Quantized electron orbits
B. The presence of neutrons
C. The arrangement of electrons
D. The nature of electromagnetic waves
The correct answer is A. Quantized electron orbits.
Explanation:
Bohr’s model introduced the idea that electrons orbit the nucleus in specific, quantized orbits, each associated with a certain energy level.
Explanation:
Bohr’s model introduced the idea that electrons orbit the nucleus in specific, quantized orbits, each associated with a certain energy level.
14. How does Bohr's model explain the stability of the atom?
A. Electrons are free to move between energy levels
B. Electrons occupy specific, fixed energy levels
C. The electron's speed determines its position
D. The atom is mostly empty space
The correct answer is A. Electrons occupy specific, fixed energy levels.
Explanation:
Bohr’s model explained atomic stability by proposing that electrons could only exist in certain quantized orbits, preventing them from spiraling into the nucleus.
Explanation:
Bohr’s model explained atomic stability by proposing that electrons could only exist in certain quantized orbits, preventing them from spiraling into the nucleus.
15. What phenomenon does the Bohr model successfully explain?
B. Spectral lines of elements
A. The stability of the nucleus
C. The behavior of protons
D. The formation of isotopes
The correct answer is B. Spectral lines of elements.
Explanation:
The Bohr model successfully explained the discrete spectral lines emitted by atoms, corresponding to electrons jumping between energy levels.
Explanation:
The Bohr model successfully explained the discrete spectral lines emitted by atoms, corresponding to electrons jumping between energy levels.
16. According to Bohr's model, how do electrons gain or lose energy?
A. By absorbing or emitting photons
B. By moving to different isotopes
C. By changing the nucleus structure
D. By varying the speed of the electron
The correct answer is A. By absorbing or emitting photons.
Explanation:
Bohr’s model states that electrons gain or lose energy by absorbing or emitting photons, which corresponds to moving between different energy levels.
Explanation:
Bohr’s model states that electrons gain or lose energy by absorbing or emitting photons, which corresponds to moving between different energy levels.
17. How did Bohr explain the emission spectra of elements?
C. Electrons transition between quantized energy levels
A. Emission occurs continuously without specific lines
B. Emission spectra depend on the nucleus type
D. Electrons absorb energy instead of emitting it
The correct answer is C. Electrons transition between quantized energy levels.
Explanation:
Bohr explained the discrete spectral lines of elements by stating that electrons transition between quantized energy levels, emitting or absorbing photons with specific energy differences.
Explanation:
Bohr explained the discrete spectral lines of elements by stating that electrons transition between quantized energy levels, emitting or absorbing photons with specific energy differences.
17. How did the Bohr model improve upon Rutherford’s model?
A. It introduced the concept of isotopes.
B. It identified the role of neutrons in the atom.
C. It explained the stability of atoms with quantized orbits.
D. It described electron shells as orbits.
The correct answer is B. It explained the stability of atoms with quantized orbits.
Explanation:
The Bohr model improved upon Rutherford’s by introducing quantized orbits for electrons, which explained the stability of atoms and the emission spectra of elements.
Explanation:
The Bohr model improved upon Rutherford’s by introducing quantized orbits for electrons, which explained the stability of atoms and the emission spectra of elements.
18. Which of the following was not a key feature of Rutherford’s model?
B. The arrangement of electrons in discrete shells.
A. The existence of a central nucleus.
C. The prediction of atomic spectra.
D. The use of the gold foil experiment.
The correct answer is B. The arrangement of electrons in discrete shells.
Explanation:
Rutherford’s model did not include the concept of discrete electron shells or quantized orbits. This feature was introduced by the Bohr model.
Explanation:
Rutherford’s model did not include the concept of discrete electron shells or quantized orbits. This feature was introduced by the Bohr model.
19. What did Rutherford’s model fail to account for in terms of atomic structure?
A. The quantization of electron orbits
B. The mass of the nucleus
C. The overall charge of the atom
D. The distribution of electrons around the nucleus
The correct answer is A. The quantization of electron orbits.
Explanation:
Rutherford’s model could not explain why electrons do not spiral into the nucleus due to electromagnetic attraction, which the Bohr model addressed with quantized orbits.
Explanation:
Rutherford’s model could not explain why electrons do not spiral into the nucleus due to electromagnetic attraction, which the Bohr model addressed with quantized orbits.
20. Who is credited with the discovery of the nucleus in the atom through the gold foil experiment?
A. Ernest Rutherford
B. Niels Bohr
C. J.J. Thomson
D. James Chadwick
The correct answer is A. Ernest Rutherford.
Explanation:
Rutherford conducted the gold foil experiment in 1911, which led to the discovery of the nucleus. He found that most of the alpha particles passed through the foil with little deflection, but some were deflected at large angles, indicating the presence of a dense nucleus at the center of the atom.
Explanation:
Rutherford conducted the gold foil experiment in 1911, which led to the discovery of the nucleus. He found that most of the alpha particles passed through the foil with little deflection, but some were deflected at large angles, indicating the presence of a dense nucleus at the center of the atom.
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