1. For each interaction, state whether it is allowed or not. If it is not allowed, state the
reason why.
• γ + p→ K+ + Λ
• γ + p→ K− + Λ
• pi− + p→ K0 + Λ
• Λ→ Σ + pi0
• Λ→ p+ pi0
• Σ+ → Λ + pi+
2. Build all the possible combinations of baryons using u, d, and s quarks. State the
strangeness and charge of the combination. Do not include antiquarks.
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3. (Circle all that apply) The strong force can
(a) rearrange quarks
(b) change an up quark to a strange quark
(c) create a quark/antiquark pair from energy
4. (Circle all that apply) The weak force can
(a) rearrange quarks
(b) change an up quark to a strange quark
(c) create a quark/antiquark pair from energy
5. What physicists originally proposed the quark model?
(a) Albert Einstein and Marie Curie
(b) Murray Gell-Mann and George Zweig
(c) Stephen Hawking and Neil deGrasse Tyson
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