Deck 34: Nuclear Fission and Fusion

Question 1

A nucleon has more potential energy with respect to a nucleus when it is

A)inside the nucleus.
B)outside the nucleus.
C)both the same

Answer 1

outside the nucleus.

Question 2

Control is exercised in a nuclear reactor by

A)absorbing excess neutrons with control rods.
B)emitting fast neutrons with a moderator.
C)both of these
D)none of these

Answer 2

absorbing excess neutrons with control rods.

Question 3

In nuclear fission and nuclear fusion reactions,the amount of mass converted to energy of other forms is

A)less than 1%.
B)about 10%.
C)about 20%.
D)about 30%.
E)more than 30%.

Answer 3

less than 1%.

Question 4

Plutonium is chemically toxic when it is

A)oxidized.
B)not oxidized.
C)oxidized or non-oxidized.
D)Plutonium in any form is not chemically toxic.

Question 5

In the fissioning of uranium,a chain reaction is caused by

A)the enormous energy release.
B)the kinetic energy of the decay products.
C)ejected neutrons.
D)the conversion of mass to energy.
E)none of these

Question 6

In a breeder reactor

A)plutonium is converted into uranium.
B)uranium is converted into plutonium.
C)both of these
D)neither of these

Question 7

A sphere of pure U-235 will explode if it is

A)hot enough.
B)shaken hard enough.
C)big enough.
D)small enough.

Question 8

Compared to the mass of a uranium nucleus before splitting,the pieces it splits into have

A)less mass.
B)the same mass.
C)more mass.

Question 9

A nucleon has more mass when it is

A)inside the nucleus.
B)outside the nucleus.
C)both the same

Question 10

The effect of putting small amounts of Pu-239 with U-238 is converting U-238 to

A)Th-239.
B)Pa-239.
C)U-235.
D)Pu-239.
E)Pb-206.

Question 11

Which will leak more neutrons,two separate lumps of uranium or the same two lumps stuck together?

A)two separate lumps
B)the same two lumps stuck together
C)both the same

Question 12

Electrical forces inside a nucleus contribute nuclear

A)stability.
B)instability.
C)both of these
D)none of these

Question 13

Three isotopes that undergo nuclear fission are

A)Th-239,U-235,Pu-239.
B)Th-238,U-235,Pu-239.
C)Th-235,U-235,Pu-239.
D)U-233,U-235,Pu-239.
E)none of these

Question 14

When a lump of uranium is broken into smaller pieces,the total surface area of the lump

A)decreases.
B)remains the same.
C)increases.

Question 15

The function of graphite in the first atomic reactor was to

A)absorb fast neutrons.
B)slow fast neutrons.
C)emit fast neutrons.
D)moderate uranium isotopes.
E)none of these

Question 16

Uranium-235,uranium-238 and uranium-239 are different

A)elements.
B)ions.
C)isotopes.
D)none of these

Question 17

U-235 and Pu-239 are both

A)radioactive isotopes.
B)fissionable isotopes.
C)heavier than lead.
D)all of these
E)none of these

Question 18

A chain reaction grows when the average number of liberated neutrons that go on to cause further fissions is

A)zero.
B)less than one.
C)one.
D)greater than one.

Question 19

When neptunium emits a beta particle the result is

A)a different isotope of neptunium.
B)uranium.
C)plutonium.
D)lead.
E)none of these

Question 20

When uranium-238 absorbs a neutron,it

A)fissions.
B)becomes a beta emitter.
C)becomes an alpha emitter.
D)emits a neutrino.
E)all of these

Question 21

A nuclear process that has relatively few radioactive by-products is

A)fission.
B)fusion.
C)Both of these have comparable radioactive by-products.

Question 22

A proton has the greatest mass in the nucleus of

A)hydrogen.
B)iron.
C)lead.
D)uranium.
E)plutonium.

Question 23

Detonation of a fusion-type hydrogen bomb is started by

A)splitting a small piece of uranium.
B)pressing together several small pieces of uranium.
C)igniting a small fission bomb.
D)turning on a laser cross fire.
E)none of these

Question 24

Detonation of a fission type atomic bomb is started by

A)splitting a small piece of uranium.
B)pressing together several small pieces of uranium.
C)igniting a small thermonuclear bomb.
D)turning on a laser cross fire.
E)none of these

Question 25

The difference in the mass of a nucleon when outside an atomic nucleus compared to inside the nucleus depends on

A)the distance away from the nucleus.
B)the atomic number of the nucleus.
C)radioactive decay.
D)isotopic abundance.
E)gamma emission.

Question 26

A nucleon has the least mass in the nucleus of

A)hydrogen.
B)iron.
C)lead.
D)uranium.
E)plutonium.

Question 27

The nucleus with the most tightly bound nucleons is

A)hydrogen.
B)iron.
C)lead.
D)uranium.
E)plutonium.

Question 28

The fusion torch is a version of

A)a cyclotron.
B)a hydrogen magnet.
C)an electron microscope.
D)a linear accelerator.
E)a mass spectrometer.

Question 29

In gaseous form,at the same temperature,the average speed of U-238 compared to the speed of U-235 is

A)less.
B)more.
C)the same.

Question 30

Between nuclear fission and nuclear fusion,radioactive by-products are more characteristic of nuclear

A)fission.
B)fusion.
C)both of these
D)neither of these

Question 31

Compared to protons,the reason neutrons are effective nuclear bullets in nuclear reactions is that a neutron has

A)more mass than a proton.
B)more penetrating power than a proton.
C)a wider cross section than a proton.
D)all of these
E)none of these

Question 32

In both fission and fusion,mass

A)is created from energy of other forms.
B)is converted to kinetic energy.
C)remains the same.

Question 33

Plutonium is not found in any appreciable amounts in natural ore deposits because it

A)is artificially created.
B)is chemically inert.
C)is a gas at room temperature.
D)has a short half-life.
E)none of these

Question 34

The nucleus with the greatest mass is

A)hydrogen.
B)iron.
C)lead.
D)uranium.
E)plutonium.

Question 35

In which of these processes is an element of matter changed into a completely different element?

A)nuclear fission
B)nuclear fusion
C)both of these
D)neither of these

Question 36

When two light atoms fuse together,mass

A)is converted to kinetic energy of neutrons.
B)is created from energy of other forms.
C)remains the same.
D)is gained.

Question 37

Present-day research in nuclear fusion uses

A)laser beams.
B)ultra-hot plasmas.
C)both of these
D)neither of these

Question 38

Energy released by the sun results from the process wherein atomic nuclei

A)break apart.
B)combine.
C)both of these
D)none of these

Question 39

The most abundant element in the universe is

A)hydrogen.
B)helium.
C)lead.
D)uranium.
E)americanium.

Question 40

The energy release in both fission and fusion is mainly in the form of

A)kinetic energy of fragments.
B)alpha radiation.
C)beta radiation.
D)gamma radiation.
E)a combination of alpha,beta,and gamma radiation.

Question 41

The mass of a nucleus is exactly equal to the sum of the masses of its individual

A)separated protons.
B)separated neutrons.
C)separated nucleons.
D)all of these
E)none of these

Question 42

Fusing two iron nuclei yields a net

A)absorption of energy.
B)release of energy.
C)neither absorption nor release of energy

Question 43

If gold were used as nuclear fuel,it would be best

A)fused.
B)fissioned.
C)either fused or fissioned.

Question 44

Fissioning a lead nucleus yields a net

A)absorption of energy.
B)release of energy.
C)neither absorption nor release of energy

Question 45

When U-239 emits a beta particle,the nucleus left behind has

A)90 protons.
B)91 protons.
C)92 protons.
D)93 protons.
E)94 protons.

Question 46

When uranium emits a beta particle,the result is a

A)different isotope of uranium.
B)transuranic element.
C)protactinium.
D)thorium.
E)depends on the isotope of uranium that emits the beta particle

Question 47

If all the uranium in the world were exhausted,breeder reactors would be

A)used much more than they are now.
B)researched more than they are now.
C)considered more seriously than they are now.
D)relics of a brief age.
E)none of these

Question 48

Fissioning an iron nucleus yields a net

A)absorption of energy.
B)release of energy.
C)neither absorption nor release of energy

Question 49

If carbon were used as nuclear fuel,it would be best

A)fused.
B)fissioned.
C)either fused or fissioned.

Question 50

When U-238 emits an alpha particle,the nucleus left behind has

A)90 protons.
B)91 protons.
C)92 protons.
D)93 protons.
E)94 protons.

Question 51

Fissioning helium would yield a net

A)absorption of energy.
B)release of energy.
C)neither absorption nor release of energy

Question 52

Which shape uses the smallest amount of material when creating a critical mass?

A)cube
B)elongated box
C)cone
D)sphere
E)none of these

Question 53

Reactions that take place in a breeder reactor change

A)elements into different elements.
B)molecules into different molecules.
C)ions into different ions.
D)all of these
E)none of these

Question 54

Hydrogen is a first-rate fuel for

A)nuclear reactions.
B)chemical reactions.
C)both of these
D)neither of these

Question 55

Fusing two helium nuclei yields a net

A)absorption of energy.
B)release of energy.
C)neither absorption nor release of energy

Question 56

If iron were used as nuclear fuel,it would be best

A)fused.
B)fissioned.
C)neither fused nor fissioned.

Question 57

The mass of a nucleon is greatest where its potential energy is

A)least.
B)greatest.

Question 58

When U-235 undergoes fission,the two nuclei that result have a total of

A)90 protons.
B)91 protons.
C)92 protons.
D)93 protons.
E)94 protons.

Question 59

Compared to the sum of the masses of all the individual nucleons in their separate states that make up a nucleus,the mass of the composite nucleus is

A)more.
B)less.
C)the same.

Question 60

Compared to the energy produced by fissioning a gram of uranium,the energy produced by fusing a gram of deuterium is

A)more.
B)less.
C)the same.

Question 61

Could you get rid of plutonium contaminating a soil sample by bombarding it with neutrons?

A)No.
B)Yes,but you might not like what you got in its place.
C)Not enough information is given.

Question 62

Which element has the smaller critical mass;U-235 that releases 2.5 neutrons per fission,or Pu-239 that releases 2.7 neutrons per fission?

A)U-235
B)Pu-239
C)Both would have the same critical mass.

Question 63

Compared to a neutron bouncing off a carbon nucleus,a neutron bouncing off a hydrogen nucleus loses

A)less speed.
B)more speed.
C)the same amount of speed.

Question 64

In a mass spectrometer,a variety of singly ionized atomic nuclei are directed into a magnetic field where they are deflected and strike a detecting screen.The particles to undergo the greatest deflection are the particles with the

A)least mass.
B)greatest mass.
C)same for all