2. Particles and Radiation (AQA)
1
An isotope of the element strontium is represented by
90
Sr
38
How many neutrons are contained in every nucleus of this isotope?
2
3
A
38
B
52
C
90
D
128
Which of the following particles has the largest specific charge?
A
electron
B
neutron
C
photon
D
proton
An isotope of iron is represented by
58
Fe
26
How many protons and neutrons are there in one atom of this isotope?
protons
neutrons
A
26
32
B
26
58
C
32
26
D
32
58
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4
Which of the following nuclei has the largest specific charge?
4
A
He
2
13
B
C
6
17
C
O
8
23
D
Na
11
5
A nuclide is represented by
235
U
92
How many nucleons does each nucleus of this nuclide contain?
A
92
B
143
C
235
D
327
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6
7
Which of the following isotopes of calcium has nuclei with the largest specific
charge?
A
calcium-40
B
calcium-42
C
calcium-43
D
calcium-46
A magnesium ion is formed by removing two electrons from an atom represented by
25
Mg
12
What is the specific charge of the magnesium ion in C kg-1?
8
9
A
3.2 x 10-19
B
1.6 x 10-18
C
7.7 x 106
D
1.6 x 107
Which of the following statements is incorrect?
A
A neutron has slightly more mass than a proton.
B
A neutron has much more mass than an electron.
C
A positron has much less mass than a proton.
D
A positron has slightly more mass than an electron.
Which fundamental force is explained by physicists in terms of an exchange of
virtual photons?
A
electromagnetic
B
gravitation
C
strong nuclear
D
weak nuclear
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10
Which of the following nuclei has the largest specific charge?
8
A
Be
4
13
B
C
6
26
C
Mg
12
33
D
P
15
11
An isotope of selenium is represented by
79
Se
34
How many nucleons does each nucleus of this selenium isotope contain?
A
34
B
45
C
79
D
113
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12
Three students posted tweets about the forces inside nuclei.
Alex: ‘The strong nuclear force acts on all nucleons, regardless of whether they are
electrically charged.’
Dmitry: ‘The electrostatic repulsive force acts on charged nucleons only.’
Ruth: ‘The strong nuclear force is repulsive up to distances of about 3 fm.’
Who is correct?
13
A
Alex only
B
Alex and Dmitry
C
Dmitry and Ruth
D
All three students
The radioactive decay of a strontium-90 nucleus into an yttrium-90 nucleus is
represented by the following equation:
90
Sr
90
Y
+ P + Q
39
38
Which particles are represented by P and Q?
14
A
- and antineutrino
B
- and neutrino
C
+ and antineutrino
D
+ and neutrino
Which fundamental force is explained by physicists in terms of an exchange of pions?
A
electromagnetic
B
gravitation
C
strong nuclear
D
weak nuclear
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15
16
When a nucleus of thorium-232 captures a neutron, it quickly undergoes two decays and transforms into a nucleus of uranium. What is the nucleon number of
the uranium nucleus?
A
231
B
232
C
233
D
234
A nucleus containing P protons and N neutrons emits an alpha particle. How many
protons and neutrons does the nucleus now contain?
number of protons number of neutrons
17
A
P-2
N-4
B
P–2
N-2
C
P–4
N-4
D
P–4
N-2
A nucleus containing P protons and N neutrons decays by emitting an alpha particle,
quickly followed by 2 - particles. How many protons and neutrons does the nucleus
now contain?
number of protons number of neutrons
18
A
P-2
N-4
B
P
N-2
C
P
N-4
D
P+2
N-2
Which particle was hypothesised to account for energy conservation in - decay?
A
antiproton
B
neutrino
C
pion
D
positron
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19
The equation represents the alpha-decay of americium-241 into an isotope of
neptunium:
241
X
Am
95
Np
+

Y
What are the values of X and Y?
20
21
X
Y
A
237
93
B
237
96
C
239
93
D
239
96
Which fundamental force is explained by physicists in terms of an exchange of W and W+ particles?
A
electromagnetic
B
gravitation
C
strong nuclear
D
weak nuclear
Which of the following particles has the greatest mass?
A
antineutrino
B
antiproton
C
electron
D
neutron
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22
23
24
25
A gamma ray photon has energy E. A second gamma ray photon has energy 2E.
Which statement about the second gamma ray photon is correct?
A
It has half the frequency of the first photon.
B
It has half the wavelength of the first photon.
C
It is moving at half the speed of the first photon.
D
It is moving at twice the speed of the first photon.
A particle has a charge -q and mass m. What are the charge and mass of its
antiparticle?
change
mass
A
+q
m
B
+q
-m
C
-q
m
D
-q
-m
The rest energy of an electron is approximately 0.5 MeV. What is produced as the
result of annihilation between a slow-moving electron and a slow-moving positron?
A
one gamma-ray photon with energy 0.5 MeV
B
one gamma ray photon with energy 1.0 MeV
C
two gamma ray photons, each with energy 0.25 MeV
D
two gamma ray photons, each with energy 0.5 MeV
Which of the following particles is unstable?
A
electron
B
neutron
C
neutrino
D
proton
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26
Positron emission tomography (PET) is an imaging technique used in medicine to
produce images of the brain and in the diagnosis and treatment of certain cancers.
A student wrote some notes about PET scans, but made one error. Which statement
is not correct?
27
A
A radioisotope that emits+ particles is injected into
the body.
B
Positrons and electrons undergo annihilation, producing
two gamma ray photons.
C
In order to conserve momentum, the two gamma rays
travel at 90o to each another.
D
The two gamma ray photons arrive at a suitable pair of
detectors simultaneously.
An X-ray photon has energy E keV. If the Plank constant is represented by h, the
speed of light by c and the charge on the electron by e, which is the correct formula
to calculate the wavelength () of the X-ray in m ?
A
=
B
=
C
D
28
hc
103 Ee
hce
103 E
103 h c
=
=
Ee
103 h c e
E
Which of the following is the exchange particle of the strong nuclear force?
A
photon
B
pion
C
positron
D
proton
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29
Which pair of graphs shows how the energy (E) of a photon depends on its
frequency (f ) and wavelength ( )?
E
E
A

f
E
E
B

f
E
E
C

f
E
E
D
f

A
B
C
D
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30
31
When a gamma ray photon interacts with an atom, it may produce an electron –
positron pair. Which statement is correct?
A
An electron-positron pair will be produced provided
the energy of the gamma ray exceeds about 1.0 MeV.
B
The electron and positron will immediately annihilate
each other.
C
The kinetic energy of the electron will always be greater
than the kinetic energy of the positron.
D
The particles will move apart at an angle of 180o to each
other.
A nucleus containing P protons and N neutrons emits a positron. How many
protons and neutrons does the nucleus now contain?
number of protons number of neutrons
32
A
P-1
N
B
P–1
N+1
C
P+1
N
D
P+1
N-1
The radioactive decay of a magnesium-50 nucleus into a chromium-50 nucleus is
represented by the following equation:
50
Mg
25
50
Cr
+ R + S
24
Which particles are represented by R and S?
A
- and antineutrino
B
- and neutrino
C
+ and antineutrino
D
+ and neutrino
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33
The equation represents electron capture:
p + e-
J + K
Which particles are represented by J and K?
34
A
neutron and antineutrino
B
neutron and neutrino
C
positron and antineutrino
D
positron and neutrino
Richard sketched some simple diagrams to represent particle interactions. In his
diagrams, time increases to the right.
Which diagram represents the annihilation of an electron and a positron?
A
Q
B
Q
C
D
A
B
C
D
35
In which group of particles do the proton, neutron and pion all belong?
A
baryons
B
hadrons
C
leptons
D
mesons
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Questions 36 – 39. Use the following data on the properties of quarks.
Type
36
37
38
Charge
Baryon number
Strangeness
u
+
2
e
3
+
1
3
0
d
-
1
e
3
+
1
3
0
s
-
1
e
3
+
1
3
-1
Which combination of quarks constitutes the antiproton?
A
u u d
B
u d d
C
u d d
D
u u d
The 0 particle has a baryon number of +1 and strangeness -1. Which combination
of quarks constitutes the 0 particle?
A
u u s
B
u d s
C
u d s
D
u d s
The + particle has a baryon number of +1 and strangeness -1. Which combination of
quarks constitutes the + particle?
A
d d s
B
d u s
C
u u s
D
u d s
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39
40
41
What are the baryon number (B) and strangeness (S) of a particle comprising an
anti-up, an anti-down and an anti-strange quark?
B
S
A
-1
-1
B
-1
+1
C
+1
-1
D
+1
+1
How many hadrons, baryons and mesons are contained in an atom of
hadrons
baryons
mesons
A
8
18
8
B
18
8
0
C
8
10
8
D
18
18
0
18
8
O?
Megan used Richard’s diagrams to represent particle interactions, with time
increasing to the right.
Which diagram could represent an electron absorbing a photon?
A
B
C
A
B
C
D
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D
42
How many quarks and/or anti-quarks comprise a meson and baryon??
meson
43
44
45
baryon
A
2
2
B
2
3
C
3
2
D
3
3
How many hadrons, baryons and leptons are contained in an atom of
hadrons
baryons
leptons
A
11
12
11
B
11
12
23
C
23
23
11
D
23
23
23
23
11
Na ?
Which particles are produced when a neutron decays?
A
proton, electron and neutrino
B
proton, positron and neutrino
C
proton, electron and antineutrino
D
proton, positron and antineutrino
When electromagnetic radiation is incident onto a clean metal surface,
photoelectrons may be emitted. Which of the following explains why photons are
not always emitted?
A
The intensity of radiation is not strong enough.
B
The frequency of the electromagnetic radiation is too large.
C
The wavelength of the electromagnetic radiation is too small.
D
The work function of the metal is too large.
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46
Some students were discussing various aspects of particle physics. A few of their
comments are listed below:
Doremi: ‘Leptons generally have lower masses than mesons.’
Farah: ‘Hadrons are generally heavier than leptons.’
Harry: ‘The hadron family of particles includes baryons and mesons.’
Vicky: ‘Examples of leptons are quarks, electrons and neutrinos.’
Which student’s statement is incorrect?
47
A
Doremi
B
Farah
C
Harry
D
Vicky
Ultraviolet radiation falls onto a clean metal plate and photoelectrons up to a
maximum energy of Ek are emitted.
What, if anything, will happen to the rate of emission of photoelectrons and the
value of Ek if the intensity of the ultraviolet radiation is increased?
emission rate
48
Ek
A
increase
increase
B
increases
stay the same
C
stay the same
increase
D
stay the same
increase
How can the threshold frequency for a metal surface be calculated?
A
Divide the work function by the Planck constant
B
Divide the Planck constant by the work function
C
Subtract the work function from the photon energy
D
Subtract the photon energy from the work function
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49
The diagram shows a number of energy levels for electrons in an atom.
n=4
n=2
-6.3
n=1
-12.6
energy/eV
n=3
-1.9
-3.8
Which of the following electron transitions would cause a photon with the shortest
wavelength to be emitted?
50
A
n=2
n=1
B
n=3
n=2
C
n=4
n=1
D
n=4
n=3
On which of the following does the maximum kinetic energy of a photoelectron
depend?
A
Photon energy only
B
Photon energy and intensity of radiation
C
Photon energy and work function
D
Photon energy, intensity of radiation and work function
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SOLUTIONS
1
B
2
A
3
A
4
A
5
C
6
A
7
C
8
D
9
A
10
A
11
C
12
B
13
A
14
C
15
C
16
B
17
C
18
B
19
A
20
D
21
D
22
B
23
A
24
D
25
B
26
C
27
A
28
B
29
D
30
A
31
B
32
D
33
B
34
D
35
B
36
D
37
C
38
C
39
B
40
D
41
B
42
B
43
C
44
C
45
D
46
D
47
B
48
A
49
C
50
C
New Objective Questions for AS and A-level Physics
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