Deck 30: Nuclear Reactions and Elementary Particles

Question 1

Name the four known fundamental forces in nature.

Answer 1

gravitation, electromagnetic, strong (nuclear), weak

Question 2

Name the exchange particles for each of the 4 "fundamental" forces.

Answer 2

strong: pion; electromagnetic: photon; weak: w and z; gravity: graviton

Question 3

Identify (name) the 12 leptons:

Answer 3

electron, muon, tauon, electron-neutrino, muon-neutrino, and tauon-neutrino; and their 6 antiparticles

Question 4

Identify with an H or L to which family, hadron or lepton, each of the following belong

-proton

A) hadron
B) lepton

Question 5

Identify with an H or L to which family, hadron or lepton, each of the following belong

-neutrino

A) hadron
B) lepton

Question 6

Identify with an H or L to which family, hadron or lepton, each of the following belong

-pion

A) hadron
B) lepton

Question 7

Identify with an H or L to which family, hadron or lepton, each of the following belong

-tauon

A) hadron
B) lepton

Question 8

A negative Q value for a reaction indicates the reaction is

A) exoergic.
B) endoergic.

Question 9

The mass of a proton is 1.6726 × 10^-27 kg and the mass of a neutron is 1.6606 × 10^-27 kg. A proton captures a neutron forming a deuterium nucleus. One would expect the mass of this nucleus to be

A) less than (1.6726 + 1.6606) × 10^-27 kg.
B) greater than (1.6726 + 1.6606) × 10^-27 kg.
C) equal to (1.6726 + 1.6606) × 10^-27 kg.

Question 10

When a target nucleus is bombarded by an appropriate beam of particles, it is possible to produce

A) a more massive nucleus, but not a less massive one.
B) a less massive nucleus, but not a more massive one.
C) a nucleus with either greater or smaller atomic number.
D) a nucleus with smaller atomic number, but not one with a greater atomic number.
E) a nucleus with greater atomic number, but not one with a smaller atomic number.

Question 11

Which Uranium isotope is the most commonly occurring isotope?

A) u-238
B) u-235
C) u-237
D) u-236

Question 12

Which uranium isotope has the largest cross section for slow neutrons?

A) U-238
B) U-235
C) U-236

Question 13

The majority of nuclear power plants depend upon which uranium isotope?

A) U-235
B) U-236
C) U-238

Question 14

One sometimes hears reference to a "20-kiloton" bomb. What does this mean?

A) It means 20,000 tons of nuclear explosive is used in the bomb.
B) It means that the number of "fissile" nuclei is equal to the number of trinitrotoluene molecules in 20,000 tons of TNT explosive.
C) It means that the total weight of the bomb (not just the uranium) is 20,000 tons.
D) This refers to the maximum pressure generated by the bomb when it explodes.
E) It means that the energy released by the bomb is equal to the energy released when 20,000 tons of TNT is exploded.

Question 15

What kind of reactor produces more fissionable fuel than it consumes?

A) breeder
B) moderated
C) heavy water
D) LOCA

Question 16

Which of the following best describes the process in which energy is released in a conventional nuclear reactor?

A) Deuterium and tritium are joined together to form helium.
B) Uranium, when bombarded by neutrons, splits into fragments and releases two or three neutrons, and these neutrons in turn strike more uranium nuclei that split, thereby setting off a chain reaction that releases energy.
C) A uranium nucleus is energized to an excited state by neutron irradiation, and it then decays by emitting beta rays and gamma rays that heat water and create steam.
D) Uranium is reacted with oxygen in a combustion process that releases large amounts of radioactivity and heat.
E) The radiation given off by a naturally radioactive substance, uranium, is collected and used to make steam.

Question 17

In a nuclear power reactor of the type used to generate electricity, a neutron bombards a uranium nucleus, causing it to split into two large pieces (fission fragments) plus two or three neutrons. Energy is released in this process in the form of electromagnetic radiation and kinetic energy. Which of the following is an accurate statement concerning what happens in such a fission process?

A) The electrical energy generated comes from the kinetic energy of the incident neutrons.
B) An intermediate step involves the fusion of protons to form helium nuclei, and energy is released in this process.
C) The total mass of the particles after fission is less than the total mass of the particles (uranium nucleus plus one neutron) before fission, and this decrease in mass $\Delta$ m is converted into energy E, where E = $\Delta$ mc².
D) The electrical energy generated comes from chemical energy stored in the electron bonds of the uranium atom.
E) Electrical energy is generated because the fission fragments are electrically charged, whereas the uranium was electrically neutral.

Question 18

What is the source of the energy the sun radiates to us?

A) nuclear fission reactions
B) cosmic rays
C) gravitational collapse
D) nuclear fusion reactions
E) chemical reactions

Question 19

Controlled fusion has been difficult to achieve primarily due to

A) the weak interaction.
B) the high temperatures required to overcome Coulomb repulsion.
C) negligible proton cross section.
D) the difficulty of slowing the fusion neutrons.

Question 20

The neutrino has

A) negligible rest mass, negative charge, and spin quantum number 1.
B) moderate rest mass, positive charge, and no spin.
C) negligible rest mass, no charge, and spin quantum number 1/2.
D) enormous rest mass, positive charge, and spin quantum number 1/2.

Question 21

Scientists were led to postulate the existence of the neutrino in order to

A) account for alpha decay.
B) maintain the conservation of energy and of momentum in beta decay.
C) explain the intense radiation emitted by quasars.
D) provide a mechanism for quark production.

Question 22

Which one of the following particles can interact with all 4 of the known forces?

A) electron
B) neutrino
C) anti-proton
D) muon
E) graviton

Question 23

What effect does an increase in the mass of the virtual exchange particle have on the range of the force it mediates?

A) increases it
B) has no appreciable effect
C) decreases it
D) decreases charged particle interactions and increases neutral particle interactions

Question 24

Which of the following is not massless?

A) neutrino
B) muon
C) graviton
D) photon

Question 25

The exchange particles for the weak force are very massive (about 100 times as massive as a proton). This would lead one to expect that the weak force would

A) act over a very long range.
B) act over a very short range.
C) only act on very massive particles.
D) be transmitted at the speed of light.

Question 26

The Feynman diagram in Figure 30-1 shows two electrons approaching each other, interacting, then leaving each other.

What particle is being exchanged during the interaction?

A) virtual photon
B) pion
C) W particle
D) neutrino

Question 27

Which of the following is not considered a fundamental particle?

A) alpha particle
B) beta particle
C) neutrino
D) muon

Question 28

Nucleons are

A) hadrons.
B) leptons.
C) baryons.

Question 29

An electron is an example of

A) a baryon.
B) a lepton.
C) a meson.
D) a hadron.

Question 30

Which of the following is true?

A) All hadrons are mesons or baryons.
B) All hadrons are nucleons.
C) All hadrons are leptons or mesons.
D) All hadrons are baryons or leptons.

Question 31

The mass of a neutron is ________ the combined mass of a proton and an electron.

A) less than
B) more than
C) equal to

Question 32

A distinctive feature of quarks is that they

A) have fractional electric charge.
B) have zero charge.
C) are always observed singly, since they do not readily interact with other particles.
D) have zero rest mass.

Question 33

The proton is believed to consist of what quark combination? (up, down, strange, charm, top, bottom)

A) bbt
B) ddu
C) uds
D) ttb
E) uud

Question 34

A quark is

A) an elementary particle which is a constituent of a hadron & a nucleon.
B) a constituent of a nucleon.
C) a constituent of a hadron.
D) an elementary particle.

Question 35

Which of the following is not believed to be composed of quarks?

A) alpha particle
B) proton
C) beta particle
D) pion
E) neutron

Question 36

The exchange particle for quarks is called

A) the gluon.
B) the stickon.
C) the epoxyon.
D) the epsilon.

Question 37

When a quark emits or absorbs a gluon, the quark changes

A) its charge.
B) its color.
C) into an antiquark.
D) its mass.
E) into a fermion.

Question 38

Mesons consist of

A) triple gluons.
B) lepton-quark pairs.
C) lepton-antilepton pairs.
D) quark-antiquark pairs.

Question 39

The grand unified theory (GUT) would reduce the fundamental forces to

A) 1.
B) 2.
C) 3.
D) 4.
E) 10.

Question 40

The grand unified theory (GUT) is a sought-after model that would unify three of the four forces of nature. Which force is the one it would not include?

A) strong
B) gravitational
C) weak
D) electromagnetic

Question 41

Starting with AC-227, assume the following sequence of decays occur: (1st) $\alpha$ decay; then (2nd) $\beta$ - decay; and finally (3rd) alpha decay. Determine the correct isotopic product after each process has occurred sequentially.

Question 42

Find the energy in MeV released in the reaction:

Mass of ²³⁸U = 238.050786 u
Mass of ²³⁴Th = 234.043583 u
Mass of ⁴He = 4.002603 u

Question 43

Determine the missing product X in the reaction:

Question 44

A Carbon-14 nucleus decays to a Nitrogen-14 nucleus by beta decay. How much energy (in MeV) is released if Carbon-14 has a mass of 14.003074 u and Nitrogen-14 has a mass of 14.003242 u?

Question 45

Find the Q value of the following reaction:

(14.003074 u) (4.002603 u) (16.999131 u) (1.007825 u)

Question 46

Complete the following nuclear reaction:

Question 47

Determine the missing reaction product:
¹n + ²³⁵U = ¹⁴¹Ba + ________ + 3(¹n )

Question 48

Starting with ²³⁵U, assume the following sequence of decays occur:
(1) (2) (3) Determine the correct isotopic product after each process has occurred sequentially.

Question 49

Consider this reaction:

(a) What is the missing daughter nuclei in the reaction?
(b) How many neutrinos are released by this reaction?

Question 50

Consider the fission reaction:

(a) Estimate the energy released in the reaction.
(b) If 3 neutrons had been released instead of 2, what energy would have been released?

Question 51

A proton strikes an Oxygen-18 nucleus producing Fluorine-18 and another particle. What other particle is produced by this nuclear reaction?

A) a neutron
B) a $\beta$ + particle
C) an alpha particle
D) a $\beta$ - particle

Question 52

In the fission reaction 235_U + 1_n $\rightarrow$ 141_Ba + 92_Kr +neutrons, the number of neutrons produced is

A) 4.
B) 2.
C) 1.
D) 3.
E) 0.

Question 53

A nuclear reaction starts with 1.71 MeV of kinetic energy and a rest energy of 28.2 GeV. If the reaction releases 1.10 MeV, what was the Q of the reaction?

A) 1.10 MeV
B) 6.60 MeV
C) 0.60 MeV
D) 28.8 GeV
E) 11.0 MeV

Question 54

The number of quarks in a deuteron is

A) 5.
B) 3.
C) 2.
D) 4.
E) 6.