Which statement, or statements, is true for all nuclei?
- They have no charge
- They contain at least one electron
- They contain an equal number of neutrons and protons
- They are positively charged
1 only
1 and 3
2 and 4
4 only
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Which statement, or statements, is true for all nuclei?
1 only
1 and 3
2 and 4
4 only
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When an alpha particle is emitted from the nucleus of a substance, which of the following remains constant for the atoms of the substance?
proton number
nucleon number
neutron number
number of electrons
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Which row is correct for the numbers of each particle in a neutral atom of ?
protons |
neutrons |
electrons |
|
A |
92 |
92 |
92 |
B |
92 |
142 |
92 |
C |
142 |
92 |
142 |
D |
234 |
142 |
92 |
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What is the unit of specific charge?
C kg−1
C kg
kg C−1
A kg−1
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What is the specific charge of a nucleus?
2.4 × 107 C kg−1
4.8 × 107 C kg−1
9.6 × 107 C kg−1
1.9 × 108 C kg−1
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Which of the following statements about specific charge is incorrect?
ions always have a non-zero specific charge
neutral atoms always have a non-zero specific charge
nuclei always have a non-zero specific charge
nuclei of isotopes of an element always have different values of specific charge
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The strong nuclear force is responsible for holding the nucleus together.
The strength of the strong nuclear force varies with the distance between nuclei, as shown on the graph below.
What does each section of the graph tell us?
1 | 2 | 3 | |
A |
at very close range the force is repulsive |
the typical nuclear separation is about 1 fm |
there is a short-range attraction between nucleons up to 3 fm apart |
B |
the strong nuclear force is mostly repulsive |
the force is at a minimum at 1 fm |
up to 3 fm the force between nucleons is attractive |
C |
at very close range the force is repulsive |
the force is at a minimum at 1 fm |
the electrostatic repulsion between protons falls to zero at 3 fm |
D |
protons repel each other due to their charges |
electrostatic force is the least at 1 fm |
the electrostatic repulsion between protons falls to zero at 3 fm |
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A nucleus of undergoes alpha decay.
Which letter represents the nucleus formed after the decay?
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In β− decay, a neutron decays to form three products.
Which row correctly identifies the three missing particles in the decay equation?
|
particle 1 |
particle 2 |
particle 3 |
A |
anti-proton |
electron |
anti-neutrino |
B |
proton |
electron |
anti-neutrino |
C |
proton |
positron |
neutrino |
D |
anti-proton |
positron |
neutrino |
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A nucleus decays by emitting an alpha particle and then a β-plus particle.
Initially, the nucleus has a mass number of 235 and a proton number of 92.
Which row shows the correct nucleon number and proton number of the nucleus after the two decays?
nucleon number |
proton number |
|
A |
231 |
89 |
B |
231 |
91 |
C |
231 |
90 |
D |
235 |
93 |
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An atom of loses three electrons.
What is the specific charge of the ion?
+ 5.5 × 106 C kg-1
- 5.5 × 106 C kg-1
+ 12 × 106 C kg-1
+ 4.4 × 107 C kg-1
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A nucleus of undergoes radioactive decay so that the decay product is .
What combination of radioactive emissions could have occurred?
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For the following decay equation, identify the type of decay and particle X.
+ X + Y
type of decay |
particle X |
particle Y |
|
A |
γ |
electron |
anti-neutrino |
B |
β-minus |
positron |
neutrino |
C |
β-plus |
positron |
neutrino |
D |
β-plus |
electron |
anti-neutrino |
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What is the ratio of the specific charge of a proton compared to the specific charge of an alpha particle?
2
4
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A radioactive nucleus absorbs a neutron, causing it to emit an α particle, and two β-minus particles. At each stage gamma radiation is also released.
What will be final nuclide be?
a new element with a smaller proton number
a new element with a higher proton number
an isotope of the original element
a stable element
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Astatine is a radioactive substance; it has a nucleon number of 218 and a proton number of 85. When it decays, it forms a polonium nucleus, emitting a β− particle and an α-particle.
What are the nucleon number and the proton number of the polonium nucleus?
nucleon number | proton number | |
A | 214 | 84 |
B | 214 | 83 |
C | 216 | 83 |
D | 215 | 82 |
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An atom of gains 2 electrons.
What is the specific charge of the ion?
+1.01 × 107 C kg–1
–1.01 × 107 C kg–1
+2.13 × 107 C kg–1
–2.13 × 107 C kg–1
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Antimatter is a particle that is an antiparticle to the corresponding particle. A positron is the antiparticle of an electron.
What is the difference between a positron and an electron?
Mass
Magnitude of charge
Charge
Spin
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An unstable nucleus decays by emitting an alpha (α) particle.
The new nucleus, and any subsequent nuclei that form, are unstable and may emit either an α or β− particle. This process continues until an isotope of the original nucleus is formed.
Including the initial alpha emission, what is the minimum number of decays that could occur?
5
4
3
2
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Two gamma photons are produced when an electron and a positron annihilate each other.
What is the minimum frequency of the gamma radiation that could be produced?
1.23 × 1014 Hz
2.47 × 1014 Hz
1.23 × 1020 Hz
2.47 × 1020 Hz
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A particular nucleus decays to form the nucleus .
The nucleus can decay in one of two possible ways to form an isotope of Thallium (Tl) or Polonium (Po).
Which isotope could not be ?
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What is the value of ?
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A sample of radioactive material contains radium , which decays by α-decay to form radon, .
What percentage of the mass of the sample would be made up from radium, after half the nuclei had decayed?
49.5 %
50.0 %
50.5 %
98.2 %
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The decay series of shows the possible nuclei that can form from alpha and beta emissions.
How many possible routes are available for to decay to a stable nucleus of ?
2
4
10
12
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Radioactive isotopes are used in medical imaging.
Two isotopes of iodine, and , are used by radiographers to give to patients in the form of iodide before taking scans.
The incomplete decay equations for these isotopes are:
Which statement gives the correct difference between these two decays?
in Decay 1 an electron neutrino is emitted, but in Decay 2 an anti-electron neutrino is emitted
in Decay 1, an electron has been absorbed but in Decay 2 a neutron has been absorbed
in Decay 1, an anti-electron neutrino is emitted, but in Decay 2 an electron neutrino is emitted
in Decay 1, a neutron becomes a proton but in Decay 2 a proton becomes a neutron
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A particular isotope decays through a series of alpha and beta emissions until a stable nucleus of forms.
Which row correctly describes the nuclides labelled 1, 2 and 3?
1 |
2 |
3 |
|
A |
|||
B |
|||
C |
|||
D |
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The graph shows how the neutron-proton ratio of stable nuclei changes as proton number increases.
For increasing proton number, which of the following changes are correct?
1 and 3
2 and 3
2, 4 and 5
2, 3 and 5
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Nuclear power stations use a fission reactor to create a nuclear reaction. A nucleus absorbs one neutron, leading to a reaction where more than one neutron is released. These neutrons in turn will set off more reactions.
This process is called a chain reaction.
Which one of these decay processes would be suitable to create a chain reaction?
____
____
____
____
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Following the development of the atomic bomb, scientists discovered that they could create elements heavier than uranium by bombarding nuclei with neutrons. These reactions, where smaller nuclei are combined to form a heavier nucleus are called fusion reactions.
Fusion reactions are balanced in exactly the same way as radioactive decay equations.
What are the missing products of these fusion reactions?
1.
2.
1 |
2 |
|
A |
||
B |
||
C |
||
D |
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Radioactive sources are used in smoke detectors. Nuclides emitting α-particles are used because α-particles have low penetrating power.
Which of these nuclides is the most likely to be a good source of α-radiation?
241-Am
18-F
89-Sr
90-Sr
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