Atomic And Nuclear Physics
Questions and Answers
- 1.
The emission of electrons from a metallic surface depends on the -------------- of the incident radiation
- A.
Intensity
- B.
Frequency
- C.
Wave length
- D.
Speed
Correct Answer
B. FrequencyExplanation
The emission of electrons from a metallic surface depends on the frequency of the incident radiation. This is because the energy of a photon is directly proportional to its frequency. When photons with sufficient energy (high frequency) strike a metal surface, they can transfer enough energy to the electrons in the metal to overcome the binding forces holding them in place, causing the emission of electrons. Therefore, the frequency of the incident radiation is a crucial factor in determining whether or not electrons will be emitted from a metallic surface.Rate this question:
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- 2.
Electrons exhibit --------
- A.
Wave properties
- B.
Both particle and wave properties
- C.
Particle properties
Correct Answer
B. Both particle and wave propertiesExplanation
Electrons exhibit both particle and wave properties. This is known as wave-particle duality, a fundamental concept in quantum mechanics. On one hand, electrons can behave as particles, having a definite position and momentum. On the other hand, they can also exhibit wave-like behavior, such as interference and diffraction patterns. This duality is supported by various experiments, such as the double-slit experiment, which demonstrates the wave-like nature of electrons. Therefore, electrons cannot be solely described as particles or waves, but rather as entities that possess characteristics of both.Rate this question:
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- 3.
The energy difference between E3 and E1 in the hydrogen atom is .......
- A.
1.5 eV
- B.
52 eV
- C.
258 eV
- D.
12.1 eV
Correct Answer
D. 12.1 eVExplanation
The energy difference between two energy levels in an atom is given by the equation ΔE = E2 - E1, where E2 is the energy of the higher level and E1 is the energy of the lower level. In the case of the hydrogen atom, the energy levels are given by the equation E = -13.6/n^2 eV, where n is the principal quantum number. Plugging in n=3 for E3 and n=1 for E1, we get ΔE = (-13.6/3^2) - (-13.6/1^2) = -1.51 - (-13.6) = 12.09 eV. Therefore, the correct answer is 12.1 eV.Rate this question:
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- 4.
The radiation of the Sun has a peak at which each photon carries 2.69 eV of energy. What is the frequency of the Sun’s radiation at this peak in its spectrum.
-
- ( Planck constant h = 6.63 x10-34 J.s) ( e = 1.6 x10-19c )
- A.
12 x 1010 Hz
- B.
6.49 x 1014 Hz
- C.
9 x 1014 Hz
- D.
4.06 x1033 Hz
Correct Answer
B. 6.49 x 1014 HzExplanation
The energy of a photon is given by the equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency. Rearranging the equation, we can solve for f: f = E/h. Given that each photon carries 2.69 eV of energy, we convert it to joules by multiplying by the conversion factor e (1.6 x 10^-19 C). Plugging in the values, we get f = (2.69 x 1.6 x 10^-19)/(6.63 x 10^-34) = 6.49 x 10^14 Hz. Therefore, the frequency of the Sun's radiation at this peak in its spectrum is 6.49 x 10^14 Hz.Rate this question:
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- 5.
Photons with a frequency of 9.3 x 1014 Hz strike the surface of a metal with work function of 3.6 eV . What is the maximum Kinetic energy of the ejected photons?
- A.
0.3 eV
- B.
5 eV
- C.
0.014 eV
- D.
1.58 eV
Correct Answer
A. 0.3 eVExplanation
The maximum kinetic energy of ejected photons can be calculated using the equation:
Kinetic energy = (Energy of incident photons) - (Work function)
The energy of incident photons can be calculated using the equation:
Energy = Planck's constant * frequency
Given that the frequency of the photons is 9.3 x 10^14 Hz, we can calculate the energy of incident photons.
Substituting the values into the equation, we get:
Energy = (6.626 x 10^-34 J s) * (9.3 x 10^14 Hz) = 6.15 x 10^-19 J
Converting this energy to electron volts (eV), we can use the conversion factor: 1 eV = 1.6 x 10^-19 J
So, the energy of incident photons is 6.15 x 10^-19 J / (1.6 x 10^-19 J/eV) = 3.84 eV
Now, subtracting the work function of 3.6 eV from the energy of incident photons, we get:
Kinetic energy = 3.84 eV - 3.6 eV = 0.24 eV
Therefore, the maximum kinetic energy of the ejected photons is 0.24 eV.Rate this question:
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- 6.
For a hydrogen atom , 1 eV = 1.60 ´ 10-19 J, h = 6.626 ´ 10-34 J • s) * What is the energy of a photon emitted as the electron drops from the sixth level to the third level?
- A.
2.58 eV
- B.
1.78 eV
- C.
1.13 eV
- D.
4 eV
Correct Answer
C. 1.13 eVExplanation
When an electron drops from a higher energy level to a lower energy level in a hydrogen atom, it emits a photon with energy equal to the difference in energy between the two levels. The energy difference between the sixth and third levels can be calculated by subtracting the energy of the third level from the energy of the sixth level. The energy of the third level is 1.13 eV, which is the given correct answer.Rate this question:
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- 7.
What is the orbital radius of the hydrogen atom when n = 8? (r1 = 5.29 x 10-11 m)
- A.
9.1 nm
- B.
1.45 nm
- C.
3.39 x 10-9 m
- D.
14 x 10-3 m
Correct Answer
C. 3.39 x 10-9 mExplanation
The orbital radius of the hydrogen atom when n = 8 is 3.39 x 10-9 m.Rate this question:
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- 8.
Which process generates energy in the Sun?
- A.
Nuclear fusion
- B.
Nuclear fission
- C.
Transmutation
Correct Answer
A. Nuclear fusionExplanation
The process that generates energy in the Sun is nuclear fusion. This is the process where two or more atomic nuclei come together to form a heavier nucleus, releasing a large amount of energy in the process. In the Sun, hydrogen nuclei combine to form helium, releasing a tremendous amount of energy in the form of light and heat. Nuclear fission, on the other hand, is the process where a heavy nucleus splits into two or more smaller nuclei, and transmutation refers to the conversion of one element into another through nuclear reactions.Rate this question:
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- 9.
What causes the particles within the nucleus of an atom to bond together?
- A.
Electromagnetism
- B.
Gravity
- C.
Weak nuclear force
- D.
Strong nuclear force
Correct Answer
D. Strong nuclear forceExplanation
The particles within the nucleus of an atom bond together due to the strong nuclear force. This force is responsible for holding the protons and neutrons together in the nucleus, overcoming the electromagnetic repulsion between the positively charged protons. The strong nuclear force is one of the fundamental forces in nature and is much stronger than the other forces such as gravity and weak nuclear force.Rate this question:
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- 10.
The nucleus of an atom consists of what particle(s)?
- A.
Protons and neutrons
- B.
Electrons
- C.
Protons and electrons
- D.
Protons
Correct Answer
A. Protons and neutronsExplanation
The nucleus of an atom consists of protons and neutrons. Protons have a positive charge and are responsible for determining the atomic number of an element, while neutrons have no charge and are responsible for adding mass to the atom. Electrons, on the other hand, are found in the electron cloud surrounding the nucleus and have a negative charge. Therefore, the correct answer is protons and neutrons.Rate this question:
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- 11.
Identify the type of radioactive decay a carbon isotope, 146C undergoes to become a nitrogen isotope 147C ?
- A.
Beta decay
- B.
Alpha decay
- C.
Gama decay
Correct Answer
A. Beta decayExplanation
Carbon-14 (146C) undergoes beta decay to become nitrogen-14 (147C). In beta decay, a neutron in the nucleus of the carbon isotope is converted into a proton, and an electron (beta particle) is emitted. This results in the formation of a nitrogen isotope with one more proton and one less neutron than the original carbon isotope.Rate this question:
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- 12.
The alpha decay of 218 84Po releases 6.115 MeV the daughter nucleus that results from this decay is :
- A.
214 82 Pb
- B.
218 84Po
- C.
216 80 Hg
- D.
281 80Bi
Correct Answer
A. 214 82 PbExplanation
In alpha decay, an alpha particle (consisting of two protons and two neutrons) is emitted from the nucleus. This causes the atomic number to decrease by 2 and the mass number to decrease by 4. In this case, the starting nucleus is 218 84Po, and after the alpha decay, the resulting nucleus will have an atomic number of 82 (decreased by 2) and a mass number of 214 (decreased by 4), which corresponds to the element lead (Pb). Therefore, the correct answer is 214 82 Pb.Rate this question:
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- 13.
One of the decay series that occurs when uranium-235 captures a neutron is the following: 10n + 23592U _______ 23692U* _______ 13755Cs + ZAX + 4 10n
- Identify the mystery nucleus.
- How much energy is released in this reaction if the mass of the system decreases by 0.205 u?
- A.
9937Rb E = 11 MeV
- B.
9537Rb E = 191 MeV
- C.
13957La E = 0.14 MeV
- D.
9537Rb E = 98.5 MeV
Correct Answer
B. 9537Rb E = 191 MeVExplanation
The mystery nucleus in the decay series is 9537Rb. This is because the reaction starts with 23592U capturing a neutron, resulting in the formation of 23692U*. The mystery nucleus is the product of the decay of 23692U*, which then decays into 13755Cs, ZAX, and 4 10n. The given answer, 9537Rb, matches the pattern of the decay series. Additionally, the energy released in this reaction is 191 MeV, as indicated by the given energy value for 9537Rb.Rate this question:
- 14.
A force between quarks that binds quarks of different "colors" together to form protons and neutrons and holds the nuclei of atoms together in spite of the protons electrostatic repulsion. It is the strongest of the fundamental forces but acts only across very short distances.
- A.
Strong nuclear Force
- B.
Weak nuclear Force
- C.
Gravitational force
- D.
Electromagnetic force
Correct Answer
A. Strong nuclear ForceExplanation
The strong nuclear force is responsible for binding quarks of different "colors" together to form protons and neutrons, as well as holding the nuclei of atoms together despite the electrostatic repulsion between protons. It is the strongest of the fundamental forces, but it only acts across very short distances.Rate this question:
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- 15.
Which of the following kinds of particles are made from quarks?
- A.
Electrons
- B.
Neutrons only
- C.
Protons and neutrons
- D.
Protons only
Correct Answer
C. Protons and neutronsExplanation
Protons and neutrons are made from quarks. Quarks are elementary particles that combine to form composite particles called hadrons. Protons are made up of two up quarks and one down quark, while neutrons are made up of one up quark and two down quarks. Electrons, on the other hand, are not made from quarks but are elementary particles themselves. Therefore, the correct answer is "Protons and neutrons".Rate this question:
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Current Version
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Mar 22, 2023Quiz Edited by
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Apr 06, 2020Quiz Created by
Rana Alahmad
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