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Review: Multiple Choice
1) In Rutherford’s -particle scattering experiment the -particles were slowed down by
a) electric fields
b) magnetic fields
c) hitting the nucleus
d) all three
2) Rutherford fired fast moving alpha particles at gold foil. The alpha particles were accelerated by
a) a cyclotron
b) an electron gun
c) nuclear decay
d) parallel plates
3) What does the -particle scattering pattern indicate about the nucleus of an atom? The nucleus
a) shows wave-particle duality
b) is made of protons and neutrons
c) is orbited by electrons
d) is very dense in mass and charge
4) In Rutherford’s planetary model, electrons are held to the nucleus by ___________ force.
a) a gravitational
b) an electrical
c) a magnetic
d) a nuclear
5) As the alpha particle got closer to the nucleus, there was an increase in
a) electric force, kinetic energy
b) electric potential energy, kinetic energy
c) electric potential energy, electric force,
d) all three
6) The closest possible approach of an -particle can be calculated using conservation of energy. You do
not need to consider air resistance or friction because they
a) are zero
b) are negligible
c) are too hard to calculate d) cancel
7) The -particles did not hit the gold nucleus. Rutherford repeated the experiment with aluminium, and
the alpha particles were able to get closer. This is because aluminium has a smaller
a) size
b) mass
c) charge
d) all three
8) In order to get close enough to hit the nucleus, it was necessary to get the -particles moving faster. If
the particles moved four times as fast the closest approach would be multiplied by
a) 0.5
b) 0.25
c) 0.125
d) 0.0625
9) Radioactive decay produces ,  and  particles. These particles are the same as
a) Helium nuclei, electrons, photons
b) protons, electrons, photons
c) protons, photons, positrons
d) none of the above
10)Bismuth-214 (Z = 83) undergoes beta decay and produces a neutrino, an electron and Polonium with
an atomic mass and number of
a) 214, 84
b) 214,82
c) 210, 84
d) 210, 82
11)Radium-226 (Z = 88) undergoes alpha decay and produces Radon with atomic mass and number of
a) 226, 86
b) 226, 89
c) 222, 86
d) 222, 89
12)When investigating beta decay, the neutrino was postulated to conserve
a) charge, momentum
b) energy, momentum
c) energy, charge
d) all of the above
13)Photons have a momentum whose value is given by
a) p = mv
b) p = h/
c) both
d) neither
14)Electrons have a momentum whose value is given by
a) p = mv
b) p = h/
c) both
d) neither
15)Rutherford’s solar system model of the atom had to be wrong because experiments showed that
a) only a few alpha particles bounced back, electrons don’t spiral into the nucleus,
b) electrons don’t spiral into the nucleus, atoms emit line spectra
c) only a few alpha particles bounced back, atoms emit line spectra
d) all three
16)The analysis of emission and absorption spectra confirmed that in an atom there are
a) discrete energy levels
b) probability clouds
c) dense nuclei
d) electrons
17)Quantum particles are different from classical particles because quantum particles
a) have wavelengths
b) have uncertain paths
c) can diffract
d) all three
18)An electron demonstrates wave-like behaviour when it
a) is bound to an atom, hits a detector
c) goes through double slits, is bound to an atom
b) goes through double slits, hits a detector
d) all three
19) Mercury’s four lowest excited states have energies (in eV) of 4.86, 6.67, 8.84 and 10.40. If an electron
is excited to the third level, it can emit photons with the following energies (in eV)
a) 8.84 , 6.67, 4.86 , 2.17, 1.81
b) 10.40, 8.84, 6.67, 4.86
c) 8.84 or 2.17 and 6.67 or 4.86 and 1.18
d) 8.84, 6.67, 4.86
20) Mercury’s four lowest excited states have energies (in eV) of 4.86 , 6.67, 8.84 and 10.40. If an
electron is in the ground state, it can absorb photons with the following energies (in eV)
a) 8.84 , 6.67, 4.86 , 2.17, 1.81
b) 10.40, 8.84, 6.67, 4.86
c) 8.84 or 2.17 and 6.67 or 4.86 and 1.18
d) 8.84, 6.67, 4.86
21)The most accurate model of the way electrons behave when bound to atoms is
a) They orbit the nucleus like a planet.
b) They jump from level to level.
c) They form standing waves around the nucleus.
d) Their position is probabilistic.
22)The electron does not spiral into the nucleus because of the
a) the Heisenberg uncertainty principle
b) the law of conservation of energy
c) the law of conservation of mass
d) the law of conservation of mass
23)Gamma radiation differs from alpha and beta radiation in that
a) the particles are neutral
b) they have no mass
c) the particles move faster
d) all of the above
24)A sample of coal initially contains 100 mg of carbon-14. This isotope has a half-life of 5,730 a. The
amount of carbon-14 remaining in the sample after 11,560 a is
a) 50 mg
b) 25 mg
c) 13 mg
d) 6 mg
25)A particle has a half-life of 1.2 x 10-6 s. This means that after 2.4 x 10-6 s the particle will
a) be 50% decayed
b) be 75% decayed
c) have a 50% chance of being decayed
d) have a 75% chance of being decayed
26)The process represented by the nuclear equation 230 Th  226 Ra + 4 He is
a) annihilation
b) alpha decay
c) beta decay
d) gamma decay
27)Radium has a half-life of 1600 years. How much of a sample will remain after 12 800 years?
a) 1/2
b)1/16
c) 1/64
d) 1/256
28)Radioactive decay must be a quantum process because
a) mass is not conserved
c) the time of decay is random
b) mass-energy is not conserved
d) all three
29)Quantum tunnelling lets a particle pass an energy barrier without sufficient energy to do so because
a) energy is not conserved in quantum physics
b) mass is converted to energy
c) of the Heisenberg Uncertainty Principle
d) of the weak nuclear force
30)When investigating beta decay, the neutrino was postulated to explain the
a) conservation of energy and momentum
b) conservation of the number of nucleons
c) ionizing effect of radiation
d) production of antiparticles
31)Nuclear and particle decays always conserve
a) mass, charge, energy
c) mass, energy, momentum
b) mass, charge, momentum
d) charge, energy, momentum
32)Alpha decay cannot be explained by classical physics because the alpha particle
a) does not have enough energy to escape, is emitted at random times
b) does not have enough energy to escape, is made of antimatter
c) is emitted at random times, is made of antimatter
d) all three
33)The fission of uranium is caused by a neutron entering the nucleus. Getting the neutron into the
nucleus is difficult. Heavy water is used in a CANDU reactor to
a) speed up the neutrons so they have more energy to break into the nucleus
b) speed up the neutrons so they have a larger wavelength and are more likely to be in the nucleus
c) slow down the neutrons so they have more energy to break into the nucleus
d) slow down the neutrons so they have a larger wavelength and are more likely to be in the nucleus
34)Fission is the nuclear process that releases energy when large nuclei split. It occurs in
a) nuclear power plants, bombs
b) stars, bombs
c) stars, nuclear power plants,
d) all three
35)There are 7 radioactive atoms in a sample. After one half life, the number of decayed atoms will be
a) 3
b) 4
c) 3.5
d) unknown
36)Particle physicists turn really fast particles by using _______________ fields
a) electric
b) magnetic
c) gravitational
d) all three
37)Electrons were used, instead of alpha particles, to explore the structure of the nucleus. They were fired
towards the nuclei of gas particles instead of metal foil. This electron scattering was different because
a) the nuclei recoiled and absorbed energy, they interacted with individual nucleons
b) the force was attractive, they interacted with individual nucleons
c) the force was attractive, the nuclei recoiled and absorbed energy
d) all three
38) An electron moves in a magnetic field of 0.20 T [down] at 5.0 Mm/s [W]. The magnetic force on it is
a) 1.6 x 10-14 N
b) 1.6 x 10-14 N [W]
c) 1.6 x 10-14 N [S]
d) zero
39)An electron passes into a magnetic field at 90o. Its resulting circular path has a radius r. if the speed of
the electron were twice as great, the radius would be
a) r
b) 2r
c) 4r
d) r/2
40)If the speed of the particle being accelerated in a cyclotron were to double, the new cyclotron
frequency would be multiplied by
a) 1
b) root 2
c) 2
d) ½
41)A charged particle is placed at rest into a uniform magnetic field. No other fields are present. It will
a) Accelerate straight forward
b) not move c) move in a circle
d) move at constant speed
42)Which forces can speed up charged particles?
a) electrical, magnetic
b) electrical, gravitational
c) magnetic forces, gravitational d) all three
43)Modern synchrotrons collide particles into each other rather than a target because
a) the resulting collisions are more energetic
b) it is easier to hit the particles
c) only these experiments conserve momentum
d) only these produce particles
44)Up quarks are +2/3 e. Down and strange quarks are -1/3 e. Which of the following makes a neutron?
a) uss
b) udd
c) usd
d) uds
45)Which quarks do you need to make a proton?
a) up up down
c) up up down and up down down
b) up down down
d) up up down or up down down
46)Which of the following particles are considered to be fundamental by physicists today?
a) electrons, protons b) electrons, neutrinos
c) protons, neutrinos
d) all three
47)Quarks have a spin of ½. Three quarks can form particles with spins of
a) 0, 1/2
b) 0, 3/2
c) 1/2, 3/2
d) all three
48)How many elementary particles are there in a e atom?
a) 8 (2 neutrons, 2 protons, 4 electrons)
c) 16 (12 quarks, 4 electrons)
b) 6 (2 neutrons, 2 protons, 2 electrons)
d) 14 (12 quarks, 2 electrons)
49)According to the quark model, decay is the result of an up quark becoming
a) a down quark and a positron
b) a strange quark and a positron
c) a down quark and an electron
d) a strange quark and an electron
50) In exploring particle tracks in a bubble chamber, physicists assume that the following are conserved
a) charge, energy
b) momentum, energy
c) momentum, charge
d) all three
51)Electrons and positrons are easy to identify in a bubble chamber because they turn with a very small
radius. This is because, compared to the other particles, they have very
a) small mass
b) small speed
c) large mass
d) large speed
52)How could you distinguish between alpha and beta particles in a cloud chamber?
a) only alpha particles make visible tracks
b) only beta particles make visible tracks
b) they bend opposite ways in a magnetic field
d) it would be impossible to do
53)An electron passes into a magnetic field at 90o. Its resulting circular path has a radius r. If the speed of
the electron were twice as great and the magnetic field were four times as strong, the radius would be
a) r
b) 2r
c) 4r
d) r/2
54)Particles in a mass spectrograph emerge from a velocity selector into a uniform magnetic field at right
angles. If the radius of the circular path of particle 1 is larger than the radius of particle 2 then
a) particle 1 has greater mass than particle 2
b) particle 1 has smaller charge than particle 2
c) the mass to charge ratio of particle 1 is larger than that of particle 2
d) particle 1 is moving faster than particle 2
Use the following bubble chamber diagram for the next five questions.
The magnetic field is into the page.
Six negative kaons enter at the bottom.
Charges are always 0, +e or –e.
2
55) Charge is conserved at
a) points 1 and 2
1
b) neither point 1 nor 2
56) The particles with the most momentum are those
a) leaving point 1
c) entering the bottom
c) just point 1
d) just point 2
b) leaving point 2
d) not enough information
57) It looks like a neutral particle was formed at point 1 because
a) conservation of momentum requires a particle leaving point 1 and moving up and to the left
b) conservation of momentum requires a particle moving up and to the left, arriving at point 2
c) conservation of charge requires that it be a neutral particle
d) all three
58) Mass is created from pure energy at
a) points 1 and 2
b) neither point 1 nor 2
c) just point 1
59)The particles leaving point 2 are the result of
a) the collision of two charged particles
c) decay of a moving charged particle
b) collision of two neutral particles
d) decay of a moving neutral particle
60)In a bubble chamber you cannot see particles that
a) are neutral, move fast
c) are charged, move fast
d) just point 2
b) are neutral, don’t move
d) are charged, don’t move
61)You have constructed a cloud chamber and placed a radioactive source inside. How could you
determine whether the particles creating the trails you see are positive, negative or neutral? Add
a) an electric field. The charged particles curve in opposite directions, the neutrals go straight.
b) an electric field. The charged particles curve in opposite directions, the neutrals are invisible.
c) a magnetic field. The charged particles curve in opposite directions, the neutrals go straight.
d) a magnetic field. The charged particles curve in opposite directions, the neutrals are invisible.
62)All the particles seen in a bubble chamber have charges of plus or minus
a) 1
b) 1 or 2/3
c) 1 or 1/3
d) 1 or 1/3 or 2/3
63)It is easier to accelerate an electron than a proton to a speed of 0.999 c because the electron
a) is smaller
b) has less mass
c) has less charge
d) is negative
64)What is the minimum energy of a photon that spontaneously produces an electron-positron pair?
a) 2 (9.11 x 10-31)(3.0 x 108)2/1.6 x 10-19) eV
b) (9.11 x 10-31)(3.0 x 108)2/1.6 x 10-19) eV
-31
8 2
c) 2 (9.11 x 10 )(3.0 x 10 ) eV
d) (9.11 x 10-31)(3.0 x 108)2 eV
65)A proton collided with an anti-proton moving with equal and opposite high speed. They annihilated
and produced a top-antitop pair. The top quarks moved
a) rapidly, perpendicular to the protons
b) rapidly, opposite each other
c) slowly, perpendicular to the protons
d) slowly, opposite each other
66) The top quark pair decayed, producing hundreds of particles. Their added momenta was
a) zero because momentum is conserved
b) non-zero, momentum is not conserved
c) non-zero because neutrinos were not detected
d) non zero because of experimental errors
67) Mass, energy and momentum are related by E2 = (pc)2 + (mc2)2. The momentum of a photon is
a) zero
b) E/c
c) E/c2
d) undefined
68) Mass, energy and momentum are related by E2 = (pc)2 + (mc2)2. The momentum of a proton moving
at 0.999999 c can be approximated by
a) zero
b) E/c
c) E/c2
d) undefined
69)Mass, energy and momentum are related by E2 = (pc)2 + (mc2)2. The energy of a stationary proton is
b) zero
b) (mc2)2
c) mc2
d) +/- mc2
70)At low speeds, the total energy of a neutron can be approximated by
a) ½ mv2
b) mc2
c) ½ mv2 + mc2
d) ½ mv2- mc2
71)Why doesn’t the moon fall into the Earth? The gravitational force
a) is cancelled by the centripetal force
b) is cancelled by the centrifugal force
c) is cancelled by the momentum
d) none of the above
72)You are in a train moving north and slowing. You throw a ball up. Relative to you the ball will land
a) to the north
b) to the south
c) to the east
d) it depends
73)You and your friend recede from each other in spacecraft in deep space without acceleration. Your
friend is moving away from you at a speed of 0.6 c. If you direct light beams at each other
a) neither beam will reach the other ship
b) each sees the light arrive at 1.2 c.
c) each sees the light arrive at 1.0000 c
d) none of these is true
74)You are an astronaut heading toward a star. In the inertial frame of the star, you are moving at a
constant speed. You can determine that you are in motion by
a) the slowing of on board clocks
b) the contraction of on board metre sticks
c) both
d) neither
75)A non-inertial frame of reference is a frame of reference that is
a) moving
b) turning
c) decelerating
d) accelerating
76)You are on a bus travelling east and there is a ball on the floor. The bus speeds up and the ball stars to
move to the back of the bus because there is
a) a real force on the ball to the west and an imaginary force on the bus to the east
b) a real force on the ball to the west and a real force on the bus to the east
c) a fictitious force on the ball to the west and an imaginary force on the bus to the east
d) a fictitious force on the ball to the west and a real force on the bus to the east
77)A bottle with a hole in the bottom is thrown straight up. After the bottle leaves the hands, the water
a) pours out on the way up only
b) pours out on the way down only
c) pours out when it is not moving at the top
d) stays in the bottle
78)Alice was in an elevator. The cable snapped. She dropped her cup of coffee in surprise. The coffee
a) stayed beside her
b) fell up quickly
c) fell down quickly d) fell down slowly
79)The time on a GPS satellite runs differently from the time on Earth. The satellite clocks run
a) faster because gravity is weaker and
slower because the satellite is moving slower
b) faster because gravity is weaker and
slower because the satellite is moving faster
c) slower because gravity is weaker and
slower because the satellite is moving slower
d) slower because gravity is weaker and
slower because the satellite is moving faster
80)The astronauts in the International Space Station appear weightless because the gravitational field
a) is zero
b) is much smaller
c) is a bit smaller
d) causes equal accelerations
81) You are in a windowless room. What can you do to determine if you are moving?
a) Put a ball on the floor and see if it starts to roll. b) See if the surface of a liquid is horizontal.
c) Both are possible tests.
d) There are no tests that you can do.
82)You are in a windowless room. What can you do to determine if you are accelerating?
a) Put a ball on the floor and see if it starts to roll. b) See if the surface of a liquid is horizontal.
c) Both are possible tests.
d) There are no tests that you can do.
83)If a small asteroid were discovered with a period four times that of the Earth`s, how many times farther
from the sun would it be located?
a) 1.6
b) 2
c) 2.5
d) 4
84) If the sun were to turn into a black hole, the Earth would
a) fall straight in
b) spiral in
c) continue to orbit
85) Light cannot escape from a black hole because the black hole has such a large
a) mass
b) weight
c) density
d) explode
d) size
86)Evidence for black holes and dark matter have come from comparing mass calculations from
a) gravitational lensing, brightness
b) orbital speeds, brightness
c) orbital speeds, gravitational lensing
d) all three
87) Black holes differ from dark matter because black holes are
a) bigger
b) made from dark matter
c) predicted by relativity
d) all three