Discussion Overview
The discussion revolves around the volume change of solids as they are cooled from room temperature to absolute zero, particularly focusing on the implications of thermal expansion coefficients and atomic spacing at low temperatures. Participants explore the calculations involved in determining the average distance between atoms and the vibrational frequencies of solids.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
- Mathematical reasoning
Main Points Raised
- One participant questions how much a typical solid shrinks when cooled to absolute zero, noting the variability of the coefficient of linear thermal expansion with temperature.
- Another participant asks for the required accuracy of the calculations, suggesting that the room temperature spacing could suffice for some purposes.
- A participant expresses the intent to calculate the average distance between atoms at room temperature to derive vibrational frequencies, acknowledging that there may be alternative methods.
- Concerns are raised about the accuracy of using room temperature coefficients for calculations, with a suggestion that a linear approximation could yield a shrinkage value that is half of what would be calculated using the room temperature coefficient.
- One participant asserts that the spacing between atoms should approach zero at absolute zero, while another clarifies that this refers to the distance between atoms rather than their centers.
- There is a discussion about defining the "distance between atoms," with some participants noting the challenges in defining atomic boundaries and suggesting the use of ionic or atomic radii for clarity.
- A participant mentions having calculated radii for various elements and allotropes, indicating a depth of prior research on the topic.
- Another participant hypothesizes about modeling atoms as rigid spheres at absolute zero, discussing the implications of thermal motion and bonding as temperature increases.
- A specific property of Ice Ih is introduced, noting its density maximum at 62 K and its behavior upon cooling above absolute zero.
Areas of Agreement / Disagreement
Participants express differing views on the accuracy required for calculations and the implications of atomic spacing at absolute zero. There is no consensus on the best approach to model atomic distances or the effects of temperature on solid volume.
Contextual Notes
Participants acknowledge the complexity of defining atomic distances and the limitations of using linear thermal expansion coefficients, which may vary with temperature. The discussion includes unresolved assumptions about atomic behavior at absolute zero.