Radioactive Substances Quiz Questions
Questions and Answers
- 1.
The nucleus of a particular form of carbon (chemical symbol C) contains 6 protons and 7 neutrons. Which of the following is the correct way to represent it?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
B. BExplanation
Option B is the correct way to represent the nucleus of this particular form of carbon. The atomic number of an element represents the number of protons in its nucleus, and in this case, carbon has 6 protons. The mass number represents the total number of protons and neutrons in the nucleus, and in this case, carbon has 6 protons and 7 neutrons. Therefore, the correct representation is 6 protons and 7 neutrons, which is shown in option B.Rate this question:
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- 2.
A particular nuclide of iron (chemical symbol Fe) is represented as follows:
- A.
56 neutrons
- B.
26 electrons
- C.
26 neutrons
- D.
26 protons
Correct Answer
D. 26 protonsExplanation
The given information states that the nuclide of iron has 26 electrons, which is equal to the atomic number of iron. The atomic number represents the number of protons in an atom. Therefore, the correct answer is 26 protons.Rate this question:
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- 3.
How many neutrons does this nuclide have?
Correct Answer
30Explanation
The number given in the question, 30, represents the number of neutrons in the nuclide.Rate this question:
- 4.
Which symbol represents a beta particle?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
B. BExplanation
The symbol "B" represents a beta particle.Rate this question:
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- 5.
Which symbol could represent an alpha particle?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
A. AExplanation
The symbol A could represent an alpha particle. Alpha particles are made up of two protons and two neutrons, which gives them a charge of +2. The symbol A is commonly used to represent the atomic mass number, which is the total number of protons and neutrons in an atom. Therefore, A is a suitable symbol to represent an alpha particle.Rate this question:
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- 6.
A radioactive nuclide X decays according to this equation:
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
D. D -
- 7.
A radioactive sample contains 8000 undecayed atoms. It hasa half-life of 4 days. What will be the number of undecayedatoms remaining after 12 days?
Correct Answer
1000Explanation
The half-life of a radioactive sample is the time it takes for half of the atoms to decay. In this case, the half-life is 4 days. After 4 days, half of the 8000 undecayed atoms will decay, leaving 4000 undecayed atoms. After another 4 days (8 days total), half of the remaining 4000 undecayed atoms will decay, leaving 2000 undecayed atoms. Finally, after 12 days (3 half-lives), half of the remaining 2000 undecayed atoms will decay, leaving 1000 undecayed atoms.Rate this question:
- 8.
The graph shows the pattern of decay of a radioactive substance. What is the half-life of the substance?
Correct Answer
8 daysExplanation
The half-life of a radioactive substance is the time it takes for half of the substance to decay. In this case, the graph shows that the substance decays completely in 8 days. Therefore, the half-life of the substance is also 8 days.Rate this question:
- 9.
The graph bellow shows the amount of undecayed material in a sample of a radioactive substance as it decayed. When the material had decayed to a very low level, the detector still recorded background radiation. From the graph, determine the background count rate.
Correct Answer
20Explanation
The background count rate can be determined by observing the graph. As the material decayed to a very low level, the detector still recorded a count rate of 20. This indicates that even when there is no radioactive material present, the detector still detects a background radiation count rate of 20.Rate this question:
- 10.
The graph bellow shows the amount of undecayed material in a sample of a radioactive substance as it decayed. When the material had decayed to a very low level, the detector still recorded background radiation. Determine the initial count rate due to the radioactive substance by calculating: initial count rate - background count rate
Correct Answer
100Explanation
The initial count rate is equal to the sum of the background count rate and the count rate due to the radioactive substance. Since the detector still recorded background radiation when the material had decayed to a very low level, we can assume that the background count rate is 0. Therefore, the initial count rate is equal to the count rate due to the radioactive substance, which is 100.Rate this question:
- 11.
Which part of the atom contains most of its mass?
- A.
Shells
- B.
Orbits
- C.
Nucleus
- D.
Neutron
Correct Answer
C. NucleusExplanation
The nucleus contains most of the mass of an atom. It is located at the center of the atom and is made up of protons and neutrons. The protons have a positive charge, while the neutrons have no charge. The electrons, which have a negative charge, are located in shells or orbits around the nucleus. However, the mass of electrons is significantly smaller compared to the mass of protons and neutrons, which is why the nucleus contains most of the mass of an atom.Rate this question:
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- 12.
The diagram shows the paths of some alpha particles as they approached a nucleus of a gold atom. Explain why the alpha particle (1) shown was back-scattered.
- A.
It's pushed back repelled by the nucleus when it passes by very near.
- B.
It's pushed back attracted by the nucleus when it passes by very near.
- C.
It's pushed back repelled by the nucleus when it passes by far away.
- D.
It's pushed back attracted by the nucleus when it passes by far away.
Correct Answer
A. It's pushed back repelled by the nucleus when it passes by very near.Explanation
The alpha particle is back-scattered because it is repelled by the nucleus when it passes by very near. As the alpha particle approaches the gold nucleus, it experiences a strong electrostatic repulsion due to the positive charge of the nucleus. This repulsion causes the alpha particle to change direction and be scattered backwards. The closer the alpha particle gets to the nucleus, the stronger the repulsion and the greater the scattering angle.Rate this question:
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- 13.
The diagram shows the paths of some alpha particles as they approached a nucleus of a gold atom. Explain why the alpha particle (2) shown was undeflected as it passed the gold nucleus.
- A.
They have unlike charges.
- B.
It's too close to the nucleus.
- C.
They have like charges but it's far away from the nucleus.
- D.
All alpha particles are deflected.
Correct Answer
C. They have like charges but it's far away from the nucleus.Explanation
The alpha particle (2) was undeflected as it passed the gold nucleus because it had like charges with the nucleus, but it was far away from it. Like charges repel each other, so if the alpha particle had been closer to the nucleus, it would have been deflected. However, since it was far away, the repulsive force between the like charges was not strong enough to cause any deflection.Rate this question:
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.webp "How many neutrons does this nuclide have?")
.webp "Which symbol could represent an alpha particle?")
.webp "The graph bellow shows the amount of undecayed material in a sample of a radioactive substance as it decayed. When the material had decayed to a very low level, the detector still recorded background radiation.
From the graph, determine the background count rate.")
.webp "The graph bellow shows the amount of undecayed material in a sample of a radioactive substance as it decayed. When the material had decayed to a very low level, the detector still recorded background radiation.
Determine the initial count rate due to the radioactive substance by calculating:
initial count rate - background count rate")
.webp "The diagram shows the paths of some alpha particles as they approached a nucleus of a gold atom.
Explain why the alpha particle (2) shown was undeflected as it passed the gold nucleus.")
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Current Version
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May 03, 2024Quiz Edited by
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May 31, 2015Quiz Created by
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