2.6 Quarks and antiquarks

• Protons and neutrons are composed of three quarks
• A proton is composed of two up quarks and one down quark.
• Quarks are found in isolation.

  False
• Order the steps to describe the composition of a proton according to the quark model:

  1️⃣ Proton is composed of three quarks

  2️⃣ The quarks are two up quarks and one down quark

  3️⃣ These quarks are called valence quarks

  4️⃣ Valence quarks determine the proton's properties
• Valence quarks are responsible for the overall properties of protons and neutrons.

  True
• Match the quark type with its electric charge:

  Up ↔️ +2/3

  Down ↔️ -1/3
• Quarks are always bound together in groups of two (mesons) or three baryons
• Quarks can exist independently.

  False
• Match the antiquark type with its electric charge:

  Anti-down ↔️ +1/3

  Anti-charm ↔️ -2/3
• A pion (π+) is composed of an up quark and an anti-down quark.
• A proton consists of two up quarks and one down quark.

  True
• The quarks that make up a neutron are two down quarks and one up quark.
• Up quarks have an electric charge of +2/3.
• Match the antiquark type with its electric charge:

  Anti-up ↔️ -2/3

  Anti-down ↔️ +1/3
• Arrange the following hadron types in order of their quark composition complexity:

  1️⃣ Mesons (quark-antiquark)

  2️⃣ Baryons (three quarks)
• A proton is composed of two up quarks and one down quark.

  True
• Quark-antiquark annihilation transforms energy into high-energy particles such as photons or gluons
• Match the particle with its quark composition:

  Proton ↔️ 2 up quarks, 1 down quark

  Neutron ↔️ 2 down quarks, 1 up quark
• Antiquarks have the same mass but opposite electric charge as their corresponding quarks
• Order the steps to describe hadron composition:

  1️⃣ Identify the type of hadron (baryon or meson)

  2️⃣ Determine the number of quarks or quark-antiquark pairs

  3️⃣ Specify the type of quarks (e.g., up, down)

  4️⃣ Combine the quarks to match the hadron's properties
• The electric charge of all quarks is either +2/3 or -1/3


  True
• What is the electric charge of a strange quark?

  -1/3
• What is the electric charge of a top quark?

  +2/3
• Hadrons are held together by the strong nuclear force
• What is the quark composition of a neutron?

  ddu
• Quark-antiquark annihilation transforms matter into energy
• Match the properties of quarks and antiquarks:

  Charge of quarks ↔️ Positive

  Charge of antiquarks ↔️ Negative

  Matter of quarks ↔️ Matter

  Matter of antiquarks ↔️ Antimatter
• Gluons carry color charge and can interact with each other


  True
• What is the quark composition of a proton?

  2 up, 1 down
• How many types of quarks are there?

  6
• What is the electric charge of an up quark?

  +2/3
• What is the quark composition of a neutron?

  2 down, 1 up
• What is the electric charge of an anti-up quark?

  -2/3
• What is the quark composition of a neutron according to the quark model?

  ddu
• The quark model provides a framework for understanding the composition of hadrons
• What fundamental particles make up the atomic nucleus?

  Protons and neutrons
• How many types of quarks are there in the standard model?

  Six
• Which quark has an electric charge of -1/3?

  Down
• A proton is composed of two up quarks and one down quark.


  True
• Hadrons are composite particles made of quarks and antiquarks, held together by the strong nuclear force