Question 1

The spin of all quarks is:
A)0.
B)1/2.
C)1.
D)1/3 or 2/3.

Accepted Answer

The spin of all quarks is 1/2 according to quantum chromodynamics theory.

Question 2

A negative muon decays to form an electron and a mu neutrino and one additional particle.The other particle must be a(n):
A)positron.
B)antineutrino.
C)neutrino.
D)photon.

Accepted Answer

The additional particle must be an antineutrino to conserve lepton number during the decay process.

Question 3

If a K⁰ meson at rest decays in 0.90 x 10^-10 s,how far will a K⁰ meson moving at 0.96 c travel through a bubble chamber? (c = 3.00 x 10⁸ m/s) A)9.3 cm B)1.1 cm C)53 cm D)42 cm

Accepted Answer

The correct answer is A.Explanation:The distance traveled by the K0 meson is given by:d = v * twhere v is the speed of the meson and t is the time it travels.We are given that the meson is moving at 0.96 c, and that it travels for 0.90 x 10^-10 s.Therefore, the distance traveled is:d = (0.96 * 3.00 x 10^8 m/s) * (0.90 x 10^-10 s) = 2.69 x 10^-2 m = 2.69 cmTherefore, the correct answer is A.

Question 4

According to the standard model,there are some cases in which a quark and its anti-quark have the same:
A)charge.
B)baryon number.
C)strangeness.
D)All of the above are always different.

Accepted Answer

In the standard model, a quark and its anti-quark always have opposite charges but have the same baryon number and strangeness. Therefore, the correct choice is C.

Question 5

Which of the following particles is made of two or more smaller particles?
A)electron
B)photon
C)proton
D)None of the above.

Accepted Answer

Protons are made up of smaller particles called quarks. Electrons and photons are fundamental particles and cannot be broken down into smaller particles.

Question 6

The S⁺,S⁰,and S^- all have strangeness of (-1).The collision of a proton and a neutron to produce a S⁰ and an anti-S^- cannot occur because it does not conserve: A)strangeness. B)charge. C)baryon number. D)All of the above.

Accepted Answer

The conservation of baryon number is violated in this case. The initial particles, a proton and neutron, have a total baryon number of 2. The final particles, S⁰ and anti-S^-, have a total baryon number of 1 + (-1) = 0. Therefore, baryon number is not conserved in this process. Strangeness and charge are conserved, as all the particles involved have a net strangeness and charge of zero.

Question 7

Which of the following decays violates conservation of lepton number?
A) 
B) 
C) 
D)

Accepted Answer

The answer of Which of the following decays violates conservation...

Question 8

Mesons are composed of ________ quarks,and baryons are composed of ________ quarks.
A)two,two
B)two,three
C)three,two
D)three,three

Accepted Answer

Mesons are composed of two quarks, one quark and one antiquark, whereas baryons are composed of three quarks. Therefore, option B is the correct choice, with mesons being composed of two quarks and baryons being composed of three quarks.

Question 9

Which of the following is not conserved?
A)lepton number
B)baryon number
C)meson number
D)energy

Accepted Answer

Lepton number, baryon number, and energy are all conserved quantities in particle interactions. However, meson number is not conserved as it is not a fundamental property of particles. Mesons are composed of a quark-antiquark pair and can be created or destroyed in interactions, so meson number is not a conserved quantity.

Question 10

According to the standard model,a quark and its antiquark may have the same:
A)spin.
B)baryon number.
C)charge.
D)All of the above may be the same.

Accepted Answer

Quarks and their corresponding antiquarks have the same spin, as spin is a quantum property that does not change when particle-antiparticle pairs are created or annihilated. However, they have opposite baryon numbers and charges.

Question 11

Which of the following particle reactions can occur?
A) 
B) 
C) 
D)

Accepted Answer

The answer of Which of the following particle reactions can...

Question 12

If a negative muon decays to form an electron-antineutrino pair and one other particle,the other particle may be a(n):
A)positron.
B)antineutrino.
C)mu neutrino.
D)electron.

Accepted Answer

When a negative muon decays, it produces an electron-antineutrino pair along with a muon neutrino. Therefore, the other particle in the decay must be a muon neutrino. The other options (positron, antineutrino, electron) are not produced in this decay process.

Question 13

If a photon produces an electron-positron pair and one other particle,the other particle may be a(n):
A)muon.
B)antineutrino.
C)neutrino.
D)photon.

Accepted Answer

The conservation of energy and momentum in particle physics allows a photon to produce an electron-positron pair only if there is another photon involved. This is because the initial photon must interact with a nucleus or another photon to satisfy these conservation laws, and the process of pair production (electron-positron creation) conserves charge, energy, and momentum with the involvement of another photon.

Question 14

The following reaction can occur by the strong interaction: p⁰ + n ® K⁺ + S^-.If the quark composition of the n is (udd),the p⁰ is and the composition of the K⁺ is ,what is the quark composition of the S^-? A)dds B)uds C)sss D)

Accepted Answer

In the reaction, we can see that a neutron (udd) has transformed into a strange particle (K) and another particle consisting of two quarks and two antiquarks (p⁰). The resulting particle, K⁺, consists of a strange quark (s) and two up quarks (u), along with an anti-strange quark (sbar) and an anti-up quark (ubar). Since the quark composition of the resulting particle has two up quarks, the new particle produced by the reaction must have one down quark to balance the quark content. Therefore, the quark composition of the S^- must be dds.

Question 15

Which of the following particle reactions cannot occur?
A) 
B) 
C) 
D)

Accepted Answer

The answer of Which of the following particle reactions cannot...

Question 16

If two quarks in an anti-proton have the color anti-red and anti-blue,the third quark must have the color:
A)red.
B)blue.
C)anti-purple.
D)anti-green.

Accepted Answer

Quarks have three types of "color" charge – red, green, and blue – and their corresponding "anti-colors" – anti-red, anti-green, and anti-blue. In order for an anti-proton to have an overall "color charge" of neutral, its three quarks must have opposite color charges. Since two of the quarks have anti-red and anti-blue colors, the third quark must have the color green. However, since all three quarks are anti-matter particles, the color of the third quark must also be anti-green (choice D).

Question 17

A proton and antiproton each with total energy 400 GeV collide head-on.What is the total energy (particles + energy)released?
A)800 GeV
B)400 GeV
C)zero
D)1 600 GeV

Accepted Answer

The total energy released in the collision is the sum of the energies of the proton and antiproton, which is 400 GeV + 400 GeV = 800 GeV.

Question 18

Experimentally,strange particles can be produced in abundance,but they decay relatively slowly.This occurs because strangeness:
A)is conserved in both their production and decay.
B)is conserved in their production but not in their decay.
C)is conserved in their decay but not in their production.
D)is not conserved in either their production or their decay.

Accepted Answer

Strange particles are particles that contain strange quarks. The conservation of strangeness means that in any interaction, the total strangeness before the interaction must be equal to the total strangeness after the interaction. This means that strange particles can be produced in abundance, but they can only decay through weak interactions which do not conserve strangeness. Therefore, strangeness is conserved in their production but not in their decay.

Question 19

The strangeness of an anti-proton is:
A)+1.
B)0.
C)-1.
D)-2.

Accepted Answer

The strangeness of an anti-proton is 0 because strangeness is a quantum number that describes the presence of strange quarks in a particle. An anti-proton, being the antiparticle of a proton, is composed of antiquarks, specifically two up antiquarks and one down antiquark, none of which are strange quarks. Therefore, its strangeness is 0.

Question 20

The S⁺,S⁰,and S^- all have strangeness of (-1).The collision of an anti-proton and a neutron may produce which of the following particles? A)S^- and S⁰ B)S⁺ and anti-S⁰ C)anti-S⁺ and S⁰ D)anti-S^- and S⁰

Accepted Answer

The collision of an anti-proton and a neutron can produce particles with a total strangeness of zero. The combination of anti-S⁺ (strangeness +1) and S⁰ (strangeness -1) results in a net strangeness of zero, conserving strangeness in the reaction.

Quiz 30: Nuclear Energy and Elementary Particles

The spin of all quarks is:

A negative muon decays to form an electron and a mu neutrino and one additional particle.The other particle must be a(n) :

If a K⁰ meson at rest decays in 0.90 x 10^-10 s,how far will a K⁰ meson moving at 0.96 c travel through a bubble chamber? (c = 3.00 x 10⁸ m/s)

According to the standard model,there are some cases in which a quark and its anti-quark have the same:

Which of the following particles is made of two or more smaller particles?

The S⁺,S⁰,and S^- all have strangeness of (-1) .The collision of a proton and a neutron to produce a S⁰ and an anti-S^- cannot occur because it does not conserve:

Which of the following decays violates conservation of lepton number?

Mesons are composed of quarks,and baryons are composed of quarks.

Which of the following is not conserved?

According to the standard model,a quark and its antiquark may have the same:

Which of the following particle reactions can occur?

If a negative muon decays to form an electron-antineutrino pair and one other particle,the other particle may be a(n) :

If a photon produces an electron-positron pair and one other particle,the other particle may be a(n) :

The following reaction can occur by the strong interaction: p⁰ + n ® K⁺ + S^-.If the quark composition of the n is (udd) ,the p⁰ is and the composition of the K⁺ is ,what is the quark composition of the S^-?

Which of the following particle reactions cannot occur?

If two quarks in an anti-proton have the color anti-red and anti-blue,the third quark must have the color:

A proton and antiproton each with total energy 400 GeV collide head-on.What is the total energy (particles + energy) released?

Experimentally,strange particles can be produced in abundance,but they decay relatively slowly.This occurs because strangeness:

The strangeness of an anti-proton is:

The S⁺,S⁰,and S^- all have strangeness of (-1) .The collision of an anti-proton and a neutron may produce which of the following particles?