Question
Solvating electrons by dissolving alkali metals in ammonia produces a solution of this color. For 10 points each:
[10e] Name this color given by cobalt and copper in the flame test. A pigment of this color that consists of repeating subunits of iron complexed to six cyanide ligands is named “Prussian.”
ANSWER: blue [accept Prussian blue]
[10h] Color can briefly be granted to metal oxide crystals by irradiating them to form these defects, in which unpaired electrons become wedged in vacancies within the crystal lattice.
ANSWER: F centers [or Farbe centers]
[10m] F-center coloration is particularly prominent in the oxide of this element, which is a white pigment that turns yellow when heated. The crystal structure of this metal’s “blende” is identical to that of diamond.
ANSWER: zinc [accept zincblende; accept zinc oxide]
<Chemistry>
Summary
| 2024 ACF Regionals @ Berkeley | 01/27/2024 | Y | 3 | 16.67 | 100% | 67% | 0% |
| 2024 ACF Regionals @ Cornell | 01/27/2024 | Y | 3 | 13.33 | 100% | 33% | 0% |
| 2024 ACF Regionals @ JMU | 01/27/2024 | Y | 9 | 12.22 | 100% | 22% | 0% |
| 2024 ACF Regionals @ Minnesota | 01/27/2024 | Y | 2 | 15.00 | 100% | 50% | 0% |
| 2024 ACF Regionals @ Nebraska | 01/27/2024 | Y | 6 | 10.00 | 100% | 0% | 0% |
| 2024 ACF Regionals @ Rutgers | 01/27/2024 | Y | 5 | 14.00 | 100% | 40% | 0% |
| 2024 ACF Regionals @ Imperial | 01/27/2024 | Y | 4 | 15.00 | 100% | 50% | 0% |
Data
| KCL | Imperial B | 10 | 0 | 0 | 10 |
| Kiel | Oxford B | 10 | 0 | 0 | 10 |
| Oxford A | Edinburgh | 10 | 0 | 10 | 20 |
| Cambridge B | Cambridge C | 10 | 0 | 10 | 20 |