Question
This quantity scales with temperature to the three-halves in gases and with temperature to the first in liquids. For 10 points each:
[10h] Name this proportionality constant between the time derivative and Laplacian of concentration. This quantity is therefore analogous to conductivity when the heat equation is used to describe mass transfer.
ANSWER: mass diffusivity [or diffusion coefficient; or diffusion constant; prompt on D; prompt on diffusion]
[10m] In most solids, though, diffusivity has the same temperature dependence as this empirical law. It is usually written as [read slowly] “k equals A times e to the negative E-sub-a over R T.”
ANSWER: Arrhenius equation
[10e] Diffusivity is linear with temperature for ions diffusing through semiconductors like this element. This metalloid is by far the most common semiconductor used in microelectronics.
ANSWER: silicon [or Si]
<Adam Silverman, Science - Chemistry> ~22822~ <Editor: Adam Silverman>
Data
Summary
| Tournament | Edition | Exact Match? | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|---|---|
| 2024 PACE NSC | 06/08/2024 | Y | 36 | 14.44 | 94% | 44% | 6% |