Chapter 30: Nuclear Physics And Radioactivity
Questions and Answers
- 1.
Which of the atomic particles has the least mass?
- A.
Electron
- B.
Proton
- C.
Neutron
- D.
Nucleon
Correct Answer
A. ElectronExplanation
The electron has the least mass among the atomic particles. This is because electrons are subatomic particles that orbit around the nucleus of an atom, and they have a very small mass compared to protons and neutrons. Protons and neutrons are located in the nucleus and are much larger and heavier in comparison. Therefore, the electron is the correct answer as it has the least mass.Rate this question:
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- 2.
The mass of an atom is
- A.
Approximately equally divided between neutrons, protons, and electrons
- B.
Evenly divided between the nucleus and the surrounding electron cloud
- C.
Concentrated in the cloud of electrons surrounding the nucleus
- D.
Concentrated in the nucleus
Correct Answer
D. Concentrated in the nucleusExplanation
The correct answer is that the mass of an atom is concentrated in the nucleus. The nucleus of an atom contains the protons and neutrons, which have much greater mass compared to the electrons. The electrons, on the other hand, have negligible mass in comparison to the protons and neutrons. Therefore, the majority of the mass of an atom is concentrated in the nucleus.Rate this question:
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- 3.
The hydrogen nucleus consists of
- A.
A single proton
- B.
A single neutron
- C.
One proton and one neutron
- D.
One proton and two neutrons
Correct Answer
A. A single protonExplanation
The hydrogen nucleus consists of a single proton. This is because hydrogen is the simplest element with atomic number 1, meaning it has one proton in its nucleus. It does not have any neutrons in its nucleus, as hydrogen-1 is the most common and stable isotope of hydrogen. Therefore, the correct answer is a single proton.Rate this question:
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- 4.
An atom's atomic number is determined by the number of
- A.
Neutrons in its nucleus
- B.
Nucleons in its nucleus
- C.
Protons in its nucleus
- D.
Alpha particles in its nucleus
Correct Answer
C. Protons in its nucleusExplanation
An atom's atomic number is determined by the number of protons in its nucleus. The atomic number represents the number of protons in an atom, which determines its identity as a specific element. Neutrons, nucleons, and alpha particles are not used to determine the atomic number of an atom.Rate this question:
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- 5.
An atom's mass number is determined by the number of
- A.
Neutrons in its nucleus
- B.
Nucleons in its nucleus
- C.
Protons in its nucleus
- D.
Alpha particles in its nucleus
Correct Answer
B. Nucleons in its nucleusExplanation
The mass number of an atom is determined by the number of nucleons in its nucleus. Nucleons include both protons and neutrons. The protons determine the atomic number of the atom, while the neutrons contribute to the mass number. Therefore, the correct answer is nucleons in its nucleus.Rate this question:
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- 6.
If an atom's atomic number is given by Z, its atomic mass by A, and its neutron number by N, which of the following is correct?
- A.
N = A + Z
- B.
N = Z - A
- C.
N = A - Z
- D.
None of the given answers
Correct Answer
C. N = A - ZExplanation
The neutron number (N) of an atom is equal to the atomic mass (A) minus the atomic number (Z). This is because the atomic mass represents the total number of protons and neutrons in the nucleus of an atom, while the atomic number represents the number of protons. Therefore, subtracting the atomic number from the atomic mass gives the number of neutrons.Rate this question:
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- 7.
When a neutron is emitted from an unstable nucleus, the atomic mass number of the nucleus
- A.
Increases by 1
- B.
Decreases by 1
- C.
Does not change
- D.
None of the given answers
Correct Answer
B. Decreases by 1Explanation
When a neutron is emitted from an unstable nucleus, it means that one neutron is being lost from the nucleus. Since the atomic mass number is the sum of the protons and neutrons in the nucleus, losing a neutron would result in a decrease in the atomic mass number by 1. Therefore, the correct answer is "decreases by 1".Rate this question:
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- 8.
The number of protons in an atom is
- A.
Zero
- B.
Equal to the number of neutrons
- C.
Equal to the number of electrons
- D.
The same for all elements
Correct Answer
C. Equal to the number of electronsExplanation
The number of protons in an atom is equal to the number of electrons. This is because protons have a positive charge, while electrons have a negative charge. In a neutral atom, the number of protons is balanced by the number of electrons, resulting in no overall charge. This balance between protons and electrons determines the atomic number of an element, which is unique for each element. Therefore, the number of protons in an atom is always equal to the number of electrons.Rate this question:
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- 9.
There is a limit to the size of a stable nucleus because of
- A.
The limited range of the strong nuclear force
- B.
The weakness of the electrostatic force
- C.
The weakness of the gravitational force
- D.
None of the given answers
Correct Answer
A. The limited range of the strong nuclear forceExplanation
The correct answer is the limited range of the strong nuclear force. The strong nuclear force is responsible for holding the nucleus of an atom together. However, this force only acts over a very short range, which means that as the size of the nucleus increases, the force becomes weaker and unable to overcome the repulsive electrostatic forces between the positively charged protons. This ultimately limits the size of a stable nucleus. The electrostatic force and gravitational force are not directly related to the stability of a nucleus.Rate this question:
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- 10.
Atoms with the same atomic number but with different numbers of neutrons are referred to as
- A.
Nucleons
- B.
Nuclides
- C.
Isotopes
- D.
None of the given answers
Correct Answer
C. IsotopesExplanation
Isotopes are atoms of the same element that have the same number of protons (atomic number) but different numbers of neutrons. This means that isotopes have different mass numbers, which is the total number of protons and neutrons in the nucleus. Isotopes have similar chemical properties but may have different physical properties due to their different mass numbers. Therefore, the correct answer is "isotopes."Rate this question:
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- 11.
Isotopes of an element have nuclei with
- A.
The same number of protons, but different numbers of neutrons
- B.
The same number of protons, and the same number of neutrons
- C.
A different number of protons, and a different number of neutrons
- D.
A different number of protons, and the same number of neutrons
Correct Answer
A. The same number of protons, but different numbers of neutronsExplanation
Isotopes of an element have nuclei with the same number of protons, but different numbers of neutrons. This means that the atomic number, which is determined by the number of protons, remains the same for all isotopes of an element. However, the mass number, which is determined by the number of protons and neutrons combined, varies among isotopes. Therefore, isotopes have the same number of protons, but different numbers of neutrons.Rate this question:
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- 12.
The atomic mass unit is defined as
- A.
The mass of a proton
- B.
The mass of an electron
- C.
The mass of a hydrogen-1 atom
- D.
One twelfth the mass of a carbon-12 atom
Correct Answer
D. One twelfth the mass of a carbon-12 atomExplanation
The atomic mass unit is defined as one twelfth the mass of a carbon-12 atom. This means that the mass of one atomic mass unit is equal to 1/12th of the mass of a carbon-12 atom. This unit is used to express the relative masses of atoms and molecules. By defining it in terms of a specific isotope of carbon, it allows for consistent and accurate measurements of atomic masses.Rate this question:
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- 13.
Compared to the masses of its separate protons and neutrons, the total mass of a stable nucleus is always
- A.
Less
- B.
The same
- C.
Greater
- D.
Zero
Correct Answer
A. LessExplanation
The total mass of a stable nucleus is always less than the combined masses of its separate protons and neutrons because a small amount of mass is converted into energy during the formation of the nucleus. This is due to the binding energy that holds the nucleus together, as described by Einstein's mass-energy equivalence principle (E=mc^2). Therefore, the mass of the nucleus is slightly less than the sum of the masses of its individual particles.Rate this question:
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- 14.
When nucleons join to form a stable nucleus, energy is
- A.
Destroyed
- B.
Absorbed
- C.
Released
- D.
Not transferred
Correct Answer
C. ReleasedExplanation
When nucleons join to form a stable nucleus, energy is released. This is because the process of nucleons coming together to form a nucleus involves the strong nuclear force, which is a very powerful force of attraction. As the nucleons come closer together and overcome the repulsive electromagnetic forces between them, energy is released in the form of binding energy. This binding energy is what holds the nucleus together and is released during the formation process. Hence, the correct answer is released.Rate this question:
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- 15.
The binding energy of a nucleus is contributed to
- A.
Radioactivity
- B.
Alpha decay
- C.
Too many neutrons
- D.
Mass defect
Correct Answer
D. Mass defectExplanation
The correct answer is mass defect. The binding energy of a nucleus is contributed to by the mass defect, which is the difference between the mass of the individual nucleons (protons and neutrons) and the mass of the nucleus as a whole. This mass difference is converted into energy according to Einstein's mass-energy equivalence principle (E=mc^2). The greater the mass defect, the greater the binding energy of the nucleus. Therefore, the mass defect plays a crucial role in determining the stability and energy release in nuclear reactions.Rate this question:
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- 16.
The binding energy per nucleon is
- A.
Directly proportional to atomic number
- B.
Inversely proportional to atomic number
- C.
The same for all atoms
- D.
None of the given answers
Correct Answer
D. None of the given answersExplanation
The binding energy per nucleon is the energy required to remove a nucleon from the nucleus of an atom. It is not directly proportional to atomic number because it depends on the specific arrangement of protons and neutrons in the nucleus. It is also not inversely proportional to atomic number because the binding energy per nucleon can vary even among atoms with the same atomic number. Therefore, the correct answer is "none of the given answers".Rate this question:
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- 17.
The binding energy per nucleon
- A.
Increases steadily as we go to heavier elements
- B.
Decreases steadily as we go to heavier elements
- C.
Is approximately constant throughout the periodic table, except for very light nuclei
- D.
Has a maximum near iron in the periodic table
Correct Answer
D. Has a maximum near iron in the periodic tableExplanation
The binding energy per nucleon refers to the amount of energy required to completely separate the nucleons (protons and neutrons) in an atomic nucleus. As we move to heavier elements, the binding energy per nucleon generally increases. However, near iron in the periodic table, the binding energy per nucleon reaches a maximum value. This is because iron has a particularly stable nucleus due to its arrangement of protons and neutrons, resulting in a higher binding energy per nucleon compared to elements before and after it.Rate this question:
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- 18.
Which of the following statements concerning the nuclear force is false?
- A.
The nuclear force is very short-ranged
- B.
The nuclear force is very weak and much smaller in relative magnitude than the electrostatic and gravitational forces
- C.
The nuclear force is attractive and not repulsive
- D.
The nuclear force acts on both protons and neutrons
Correct Answer
B. The nuclear force is very weak and much smaller in relative magnitude than the electrostatic and gravitational forcesExplanation
The nuclear force is not weak and much smaller in relative magnitude compared to the electrostatic and gravitational forces. The nuclear force is actually very strong and acts over very short distances, which makes it much stronger than both the electrostatic and gravitational forces.Rate this question:
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- 19.
Compared to the electrostatic force, the nuclear force between adjacent protons in a nucleus is
- A.
Much weaker
- B.
About the same size
- C.
Only slightly larger
- D.
Much larger
Correct Answer
D. Much largerExplanation
The nuclear force between adjacent protons in a nucleus is much larger compared to the electrostatic force. This is because the nuclear force is responsible for holding the protons together in the nucleus, overcoming the electrostatic repulsion between positively charged protons. The nuclear force is a short-range force that acts only within the nucleus, while the electrostatic force acts over longer distances. Therefore, the nuclear force is much stronger than the electrostatic force in this context.Rate this question:
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- 20.
Alpha rays can penetrate
- A.
Air only
- B.
A piece of paper
- C.
Several millimeters of aluminum
- D.
Several centimeters of lead
Correct Answer
B. A piece of paperExplanation
Alpha rays are made up of positively charged particles called alpha particles, which are relatively large and heavy. Due to their size and charge, alpha particles interact strongly with matter and are easily absorbed. They can be stopped by a sheet of paper because the particles collide with the atoms in the paper, losing energy and eventually coming to a stop. However, they can penetrate air because the density of air is much lower than that of a solid material like paper. Alpha rays cannot penetrate several millimeters of aluminum or several centimeters of lead because these materials are denser and have more atoms for the alpha particles to interact with, resulting in greater absorption.Rate this question:
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- 21.
Beta rays can penetrate
- A.
Air only
- B.
A piece of paper
- C.
Several millimeters of aluminum
- D.
Several centimeters of lead
Correct Answer
C. Several millimeters of aluminumExplanation
Beta rays are high-energy electrons or positrons that can penetrate certain materials. They have a moderate penetrating power and can pass through air and thin materials like paper easily. However, they are stopped or absorbed by denser materials like aluminum and lead. Several millimeters of aluminum is enough to block or attenuate beta rays, making it an effective shield against them.Rate this question:
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- 22.
Gamma rays can penetrate
- A.
Air only
- B.
A piece of paper
- C.
Several millimeters of aluminum
- D.
Several centimeters of lead
Correct Answer
D. Several centimeters of leadExplanation
Gamma rays are a form of electromagnetic radiation with high energy and short wavelength. They have the ability to penetrate various materials due to their high energy. While they can easily pass through air and a piece of paper, they require thicker barriers to be absorbed or stopped. Several centimeters of lead, being a dense material, is capable of effectively blocking gamma rays. Therefore, it is the correct answer as it provides a sufficient barrier for gamma ray absorption.Rate this question:
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- 23.
An α particle is also known as
- A.
An electron
- B.
A positron
- C.
Helium nucleus
- D.
A photon
Correct Answer
C. Helium nucleusExplanation
An α particle is commonly known as a helium nucleus. It consists of two protons and two neutrons, making it identical to the nucleus of a helium atom. It is called an α particle because it is emitted during certain types of radioactive decay, such as alpha decay. It has a positive charge and is relatively large compared to other subatomic particles like electrons or photons.Rate this question:
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- 24.
A ß- particle is also known as
- A.
An electron
- B.
A positron
- C.
A helium nucleus
- D.
A photon
Correct Answer
A. An electronExplanation
An α-particle is not an electron, positron, helium nucleus, or a photon. An α-particle is actually a helium nucleus, consisting of two protons and two neutrons. Therefore, the correct answer is "a helium nucleus".Rate this question:
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- 25.
A ß+ particle is also known as
- A.
An electron
- B.
A positron
- C.
A helium nucleus
- D.
A photon
Correct Answer
B. A positronExplanation
A ß+ particle is also known as a positron. This is because a positron is a subatomic particle with the same mass as an electron but with a positive charge. It is the antimatter counterpart of an electron, meaning that it has the opposite charge. When a positron collides with an electron, they annihilate each other, releasing energy in the form of gamma rays. Positrons are commonly used in medical imaging techniques such as positron emission tomography (PET) scans.Rate this question:
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- 26.
A gamma ray is also known as
- A.
An electron
- B.
A positron
- C.
A helium nucleus
- D.
A photon
Correct Answer
D. A photonExplanation
A gamma ray is a high-energy electromagnetic radiation that is often emitted during radioactive decay or nuclear reactions. It is not an electron, positron, or a helium nucleus, which are all particles with mass. Instead, a gamma ray is a type of photon, which is a particle of light that has no mass.Rate this question:
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- 27.
A γ-ray is also known as
- A.
An electron
- B.
A positron
- C.
A helium nucleus
- D.
A photon
Correct Answer
D. A photonExplanation
A γ-ray is a high-energy electromagnetic wave, similar to X-rays and light, but with much higher energy. It is produced during radioactive decay or nuclear reactions. Since it is an electromagnetic wave, it is composed of photons. Therefore, the correct answer is "a photon."Rate this question:
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- 28.
An alpha particle will be attracted to a
- A.
Gamma ray
- B.
Proton
- C.
Positive charge
- D.
Negative charge
Correct Answer
D. Negative chargeExplanation
An alpha particle is a positively charged particle consisting of two protons and two neutrons. According to the principles of electrostatics, opposite charges attract each other. Therefore, an alpha particle, being positively charged, will be attracted to a negative charge.Rate this question:
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- 29.
When an alpha particle is emitted from an unstable nucleus, the atomic mass number of the nucleus
- A.
Increases by 2
- B.
Decreases by 2
- C.
Increases by 4
- D.
Decreases by 4
Correct Answer
D. Decreases by 4Explanation
When an alpha particle is emitted from an unstable nucleus, it consists of two protons and two neutrons. Since the alpha particle is being emitted, it means that the nucleus is losing these two protons and two neutrons. As a result, the atomic mass number of the nucleus decreases by 4 because the mass of the alpha particle is subtracted from the original nucleus.Rate this question:
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- 30.
Alpha particles have an atomic mass equal to
- A.
1
- B.
2
- C.
4
- D.
6
Correct Answer
C. 4Explanation
Alpha particles have an atomic mass equal to 4. Alpha particles are made up of two protons and two neutrons, giving them a total of four atomic mass units. This makes them heavier than a single proton or neutron, which have an atomic mass of 1. Alpha particles are commonly emitted during radioactive decay processes, such as in the decay of uranium or radon.Rate this question:
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- 31.
When an alpha particle is emitted from an unstable nucleus, the atomic number of the nucleus
- A.
Increases by 2
- B.
Decreases by 2
- C.
Increases by 4
- D.
Decreases by
Correct Answer
B. Decreases by 2Explanation
When an alpha particle is emitted from an unstable nucleus, it consists of two protons and two neutrons. Since the alpha particle is being emitted, it means that the nucleus is losing these particles. As protons determine the atomic number of an element, losing two protons means that the atomic number decreases by 2. Therefore, the correct answer is "decreases by 2".Rate this question:
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- 32.
The expression (MX - MY - Ma) x 931.5 represents
- A.
The binding energy of the nucleus X
- B.
The binding energy of the nucleus Y
- C.
The energy released when nucleus X undergoes alpha decay
- D.
The energy released when nucleus Y undergoes alpha decay
Correct Answer
C. The energy released when nucleus X undergoes alpha decayExplanation
The expression (MX - MY - Ma) x 931.5 represents the energy released when nucleus X undergoes alpha decay. This can be inferred from the fact that the expression involves the difference between the masses of nucleus X (MX) and nucleus Y (MY), subtracted by the mass of the alpha particle (Ma), multiplied by a constant factor (931.5 MeV/c^2). This expression is commonly used in nuclear physics to calculate the energy released during radioactive decay processes, such as alpha decay.Rate this question:
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- 33.
In beta decay
- A.
A proton is emitted
- B.
A neutron is emitted
- C.
An electron is emitted
- D.
An electron decays into another particle
Correct Answer
C. An electron is emittedExplanation
In beta decay, an electron is emitted. This process occurs when a neutron in the nucleus of an atom transforms into a proton, and in order to maintain charge balance, an electron is emitted. This electron is known as a beta particle and carries a negative charge. Beta decay is a type of radioactive decay and is commonly observed in isotopes with an excess of neutrons.Rate this question:
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- 34.
During ß+ decay
- A.
A neutron is transformed to a proton
- B.
A proton is transformed to a neutron
- C.
A neutron is ejected from the nucleus
- D.
A proton is ejected from the nucleus
Correct Answer
B. A proton is transformed to a neutronExplanation
During β+ decay, a proton is transformed into a neutron. This occurs when a proton in the nucleus undergoes a transformation, resulting in the emission of a positron and a neutrino. The proton is converted into a neutron, which increases the number of neutrons in the nucleus while decreasing the number of protons. This process helps to stabilize the nucleus by balancing the number of protons and neutrons.Rate this question:
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- 35.
During ß- decay
- A.
A neutron is transformed to a proton
- B.
A proton is transformed to a neutron
- C.
A neutron is ejected from the nucleus
- D.
A proton is ejected from the nucleus
Correct Answer
A. A neutron is transformed to a protonExplanation
During β- decay, a neutron is transformed into a proton. This process occurs when a neutron in the nucleus of an atom decays into a proton, releasing an electron and an antineutrino. This decay is accompanied by the conversion of one of the down quarks within the neutron into an up quark, resulting in a change in charge from zero (neutron) to +1 (proton). This transformation is a fundamental process in nuclear physics and is responsible for the stability of atomic nuclei.Rate this question:
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- 36.
When a ß+ particle is emitted from an unstable nucleus, the atomic number of the nucleus
- A.
Increases by 1
- B.
Decreases by 1
- C.
Does not change
- D.
None of the given answers
Correct Answer
B. Decreases by 1Explanation
When a ß+ particle (also known as a positron) is emitted from an unstable nucleus, it means that a proton is being converted into a neutron. Since a proton has an atomic number of 1 and a neutron has an atomic number of 0, the atomic number of the nucleus decreases by 1 when a ß+ particle is emitted.Rate this question:
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- 37.
When a ß- particle is emitted from an unstable nucleus, the atomic number of the nucleus
- A.
Increases by 1
- B.
Decreases by 1
- C.
Does not change
- D.
None of the given answers
Correct Answer
A. Increases by 1Explanation
When a β-particle is emitted from an unstable nucleus, it is actually an electron that is being emitted. The emission of a β-particle results in the conversion of a neutron into a proton. Since the number of protons in an atom determines its atomic number, the atomic number of the nucleus increases by 1 when a β-particle is emitted.Rate this question:
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- 38.
When a ß- particle is emitted from an unstable nucleus, the atomic mass number of the nucleus
- A.
Increases by 1
- B.
Decreases by 1
- C.
Does not change
- D.
None of the given answers
Correct Answer
C. Does not changeExplanation
When a β-particle (symbolized by ß) is emitted from an unstable nucleus, the atomic mass number of the nucleus does not change. This is because a β-particle is an electron or a positron, which has negligible mass compared to the nucleus. The emission of a β-particle only affects the atomic number of the nucleus, as it changes the number of protons, but not the number of neutrons. Therefore, the correct answer is that the atomic mass number of the nucleus does not change.Rate this question:
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- 39.
The existence of the neutrino was postulated in order to explain
- A.
Alpha decay
- B.
Gamma emission
- C.
Beta decay
- D.
Fission
Correct Answer
C. Beta decayExplanation
The existence of the neutrino was postulated in order to explain beta decay. Beta decay is a radioactive decay process in which a nucleus emits a beta particle (either an electron or a positron) and transforms into a different element. However, according to the law of conservation of energy and momentum, the energy and momentum of the emitted beta particle did not add up in experiments. To resolve this discrepancy, Wolfgang Pauli proposed the existence of a neutral and nearly massless particle, which he called the neutrino. The neutrino carries away the missing energy and momentum in beta decay, making the conservation laws valid.Rate this question:
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- 40.
Which of the following is most nearly the same as a gamma ray?
- A.
An alpha particle
- B.
A beta ray
- C.
Visible light
- D.
A proton
- E.
A neutron
Correct Answer
C. Visible lightExplanation
Gamma rays are a type of electromagnetic radiation with high energy and short wavelength. Visible light is also a type of electromagnetic radiation, but with lower energy and longer wavelength compared to gamma rays. Both gamma rays and visible light are part of the electromagnetic spectrum, but they differ in terms of energy and wavelength. Therefore, visible light is the option that is most nearly the same as a gamma ray.Rate this question:
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- 41.
When a gamma ray is emitted from an unstable nucleus,
- A.
The number of neutrons and the number of protons drop by two
- B.
The number of neutrons drops by one and the number of protons increases by one
- C.
There is no change in either the number of neutrons or the number of protons
- D.
None of the given answers
Correct Answer
C. There is no change in either the number of neutrons or the number of protonsExplanation
When a gamma ray is emitted from an unstable nucleus, there is no change in either the number of neutrons or the number of protons. Gamma rays are high-energy photons that are emitted during a nuclear decay process. Unlike alpha and beta particles, gamma rays do not carry any charge or mass, so they do not affect the number of neutrons or protons in the nucleus. Therefore, the number of neutrons and protons remains the same before and after the emission of a gamma ray.Rate this question:
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- 42.
Which particle has the most mass?
- A.
Alpha
- B.
Beta
- C.
Electron
- D.
Gamma
Correct Answer
A. AlphaExplanation
The alpha particle has the most mass compared to the other particles listed (beta, electron, and gamma). An alpha particle consists of two protons and two neutrons, which gives it a mass of approximately four atomic mass units (AMU). In comparison, a beta particle (an electron or a positron) has a mass of only about 1/1836 AMU, and an electron and gamma particle have negligible mass. Therefore, the alpha particle has the most mass among these options.Rate this question:
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- 43.
In all three types of radioactive decay, what value is conserved in addition to electric charge, energy, and momentum?
- A.
Atomic number
- B.
Neutron number
- C.
Nucleon number
- D.
None of the given answers
Correct Answer
C. Nucleon numberExplanation
The nucleon number is conserved in addition to electric charge, energy, and momentum in all three types of radioactive decay. The nucleon number refers to the total number of protons and neutrons in the nucleus of an atom. During radioactive decay, the nucleus may undergo changes, but the total number of nucleons remains the same. This conservation of nucleon number helps to maintain the overall stability and balance within the nucleus.Rate this question:
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- 44.
What happens to the half-life of a radioactive substance as it decays?
- A.
It remains constant
- B.
It increases
- C.
It decreases
- D.
It could do any of these
Correct Answer
A. It remains constantExplanation
The half-life of a radioactive substance refers to the time it takes for half of the substance to decay. As the substance continues to decay, the amount of radioactive material decreases, but the half-life remains constant. This means that regardless of how much of the substance is left, it will always take the same amount of time for half of it to decay. Therefore, the correct answer is that the half-life of a radioactive substance remains constant.Rate this question:
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- 45.
In radioactive dating, carbon-14 is often used. This nucleus emits a single beta particle when it decays. When this happens, the resulting nucleus is
- A.
Still carbon-14
- B.
Boron-14
- C.
Nitrogen-14
- D.
Carbon-15
- E.
Carbon-13
Correct Answer
C. Nitrogen-14Explanation
When carbon-14 decays, it emits a beta particle, which is essentially an electron. This results in the transformation of a neutron into a proton within the carbon-14 nucleus. As a result, the resulting nucleus has one more proton and one less neutron than carbon-14. Since nitrogen-14 has one more proton and one less neutron than carbon-14, it is the correct answer.Rate this question:
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- 46.
The type of detector that uses a magnetic field to curve charged particles is a
- A.
Geiger tube
- B.
Scintillation counter
- C.
Cloud chamber
- D.
Bubble chamber
- E.
Spark chamber
Correct Answer
D. Bubble chamberExplanation
A bubble chamber is a type of detector that uses a magnetic field to curve charged particles. As charged particles pass through the chamber, they ionize the liquid inside, creating a trail of bubbles. The magnetic field causes the charged particles to curve, and the resulting bubble tracks can be photographed and analyzed to determine the properties of the particles. This makes the bubble chamber a valuable tool in particle physics research.Rate this question:
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- 47.
The type of detector that uses liquid hydrogen is a
- A.
Geiger tube
- B.
Scintillation counter
- C.
Cloud chamber
- D.
Bubble chamber
- E.
Spark chamber
Correct Answer
D. Bubble chamberExplanation
A bubble chamber is a type of detector that uses liquid hydrogen. It is a device used in particle physics to observe the tracks of electrically charged particles. When a charged particle passes through the liquid hydrogen, it ionizes the atoms and creates a trail of bubbles. These bubbles can be photographed and analyzed to study the properties and behavior of the particles. Other detectors mentioned, such as Geiger tubes, scintillation counters, cloud chambers, and spark chambers, have different principles of operation and do not use liquid hydrogen.Rate this question:
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- 48.
Cloud chambers have been replaced by bubble chambers because
- A.
The radioactive clouds were too dangerous to work with
- B.
The density of fluids is greater than the density of vapors
- C.
Bubble chambers tend to be larger and more expensive
- D.
Gamma rays are visible in bubble chambers, but not in cloud chambers
Correct Answer
B. The density of fluids is greater than the density of vaporsExplanation
Cloud chambers have been replaced by bubble chambers because the density of fluids is greater than the density of vapors. This means that bubble chambers can detect and track particles more effectively than cloud chambers. The higher density of fluids allows for better visualization and measurement of particle tracks, making bubble chambers a more suitable choice for particle physics experiments.Rate this question:
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- 49.
An element with atomic mass number of 14 and atomic number 6 has how many protons?
- A.
6
- B.
8
- C.
14
- D.
20
Correct Answer
A. 6Explanation
The atomic number of an element represents the number of protons in its nucleus. In this question, the element has an atomic number of 6, which means it has 6 protons. Therefore, the correct answer is 6.Rate this question:
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- 50.
An element with atomic mass number of 14 and atomic number 6 has how many neutrons?
- A.
6
- B.
8
- C.
14
- D.
20
Correct Answer
B. 8Explanation
The atomic mass number represents the total number of protons and neutrons in an atom. The atomic number represents the number of protons in an atom. To find the number of neutrons, subtract the atomic number from the atomic mass number. In this case, the element has an atomic number of 6 and an atomic mass number of 14. Subtracting 6 from 14 gives us 8, which is the number of neutrons in the atom.Rate this question:
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Nov 07, 2023Quiz Edited by
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Oct 16, 2012Quiz Created by
Drtaylor