Question
The burning of this element occurs as the very brief final stage of nuclear fusion in post-main-sequence stars. For 10 points each:
[10h] Name this element whose fusion leads eventually to an iron core. Type Ia (“one-A”) supernovae are distinguished from type Ib and type Ic supernovae by the presence of a strong absorption band at 615 nanometers corresponding to this element.
ANSWER: silicon [or Si; accept silicon burning or silicon fusion]
[10e] In silicon burning, silicon nuclei successively fuse with these particles. Photodisintegration of these particles produces two protons and two neutrons, since they are equivalent to helium-4 nuclei.
ANSWER: alpha particles [or alpha rays or alpha radiation]
[10m] After fusion stops, mechanisms like photodisintegration and electron capture remove degeneracy pressure support for the star, accelerating this process. Type Ia supernovae uniquely do not result from this process.
ANSWER: core collapse [accept core-collapse supernova; prompt on collapse]
<Other Science>
Summary
| 2024 ACF Regionals @ Berkeley | 01/27/2024 | Y | 3 | 30.00 | 100% | 100% | 100% |
| 2024 ACF Regionals @ Cornell | 01/27/2024 | Y | 3 | 10.00 | 100% | 0% | 0% |
| 2024 ACF Regionals @ JMU | 01/27/2024 | Y | 9 | 14.44 | 89% | 44% | 11% |
| 2024 ACF Regionals @ Minnesota | 01/27/2024 | Y | 2 | 10.00 | 50% | 50% | 0% |
| 2024 ACF Regionals @ Nebraska | 01/27/2024 | Y | 5 | 14.00 | 100% | 40% | 0% |
| 2024 ACF Regionals @ Rutgers | 01/27/2024 | Y | 5 | 20.00 | 80% | 80% | 40% |
| 2024 ACF Regionals @ Imperial | 01/27/2024 | Y | 4 | 17.50 | 100% | 50% | 25% |
Data
| Cambridge B | Cambridge C | 10 | 10 | 10 | 30 |
| Imperial B | KCL | 0 | 10 | 0 | 10 |
| Oxford B | Kiel | 0 | 10 | 0 | 10 |
| Edinburgh | Oxford A | 0 | 10 | 10 | 20 |