Packet 2: Bonus 1
Answer the following about clock reactions. For 10 points each:
[10m] This element undergoes a namesake clock reaction in which it complexes with starch to form a deep blue color. This element’s radioactive isotope 131 is used to treat Graves’ disease.
ANSWER: iodine [or I; accept iodine clock reaction; prompt on iodide or iodized by asking “what’s the element?”]
[10e] The chemical traffic light, which moves from red to yellow to green when shaken, is an example of this type of reaction whose name is a portmanteau indicating the loss and gain of electrons.
ANSWER: redox reaction [or reduction-oxidation reaction or oxidation-reduction reaction; reject “reduction” reaction or “oxidation” reaction alone]
[10h] These chemicals’ clock reaction occurs at a known rate, allowing calculation of the rates of reactions involving them during which electron transfer is shown using fishhook arrows. RAFT polymerization is catalyzed by these chemicals.
ANSWER: free radicals [accept radical clock; accept free radical polymerization; accept reversible-deactivation radical polymerization]
<Chemistry — Andrew Gao> | SHOW-ME Four Packet 2
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 21 | 16.67 | 62% | 76% | 29% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Merrol Hyde A | USN C | 0 | 10 | 0 | 10 | E |
| Owensboro | Merrol Hyde B | 0 | 10 | 0 | 10 | E |
| Portland High | Harpeth Hall | 0 | 0 | 0 | 0 | |
| USN A | Athens Bible School | 10 | 10 | 10 | 30 | MEH |
| USN B | Franklin Road Academy | 10 | 10 | 0 | 20 | ME |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| Rube Goldberg XIX | 11/20/2025 | ✓ | 11 | 13.64 | 36% | 82% | 18% |
| SHOW-ME Four Nationwide HS | 11/20/2025 | ✓ | 5 | 26.00 | 100% | 100% | 60% |
| SPOOKY IX | 11/20/2025 | ✓ | 5 | 14.00 | 80% | 40% | 20% |