Talk:Compressibility

message: Sorry to the person who did the bulk of the writing on this page, but you've got the symbols backward. B is for bulk modulus and K is for compressibility. When I get some time, I will try to repair the damage, but it's going to take a lot of work as the error is spread across several pages. Elert 20:50, 2 December 2007 (UTC)
replies: text: The symbols may not be the best choice, but they are not in error. Ive seen bulk modulus mostly as K as (Atkins-Physical Chemistry, Landau and Lifshitz-Theory of Elasticity) sometimes as B (Symon-Mechanics). Ive seen compressibility always as a Greek letter sometimes as β sometimes as κ. When faced with these options, I think the bottom line should be IUPAC. IUPAC specifies "k" for the isothermal compressibility, but does not specify a symbol for the bulk modulus. (Perhaps its not a commonly used chemical parameter). I would be in favor of changing  the symbol for compressibility to "k" but go slow on changing bulk modulus to "B". PAR 00:08, 3 December 2007 (UTC)
replies: text: This is a very old thread but I'd like to fix this problem. I agree that the IUPAC/IUPAP notations should be used in this article. The link provided above appears to be dead but I do see this:  . The document specifies κT for the isothermal coefficient, κs for the adiabatic coefficient, and K for the bulk modulus. Any discussion toward consensus? KeeYou Flib (talk) 19:29, 21 February 2021 (UTC)

text:  I've just had a look at Atkins and de Paula's Physical Chemistry: Thermodynamics, Structure & Change (10th ed. 2014) and they use κT for the isothermal compressibility; presumably "K" was used in an early edition pre-2007. In fact they use IUPAC notation throughout the text. KeeYou Flib (talk) 16:30, 22 February 2021 (UTC)

text: I've also seen β used for bulk modulus (in https://www.semanticscholar.org/paper/Multicomponent-Multiphase-Equation-of-State-for-Kerley-Chhabildas/cb0d52699ffda4efa2781fcd9236a14b34bf5958).DubleH (talk) 08:36, 31 March 2021 (UTC)
replies: text:  Some authors use beta for the compressibility, others for the bulk modulus! Just goes to show that different authors of different texts in different fields tend to use their own favorite symbols, while certain fields favor the use of some symbols over others. This is why I'd prefer to stick with IUPAC symbol recommendations; at least there's an authority making these decisions. KeeYou Flib (talk) 21:03, 31 March 2021 (UTC)
thread_title:  Bulk modulus (B) compressibility (K) 

message: How about s instead of S, because T and s are intrinsic (that is, specific) properies, while S is an extrinsic property.  Alternative, something like n could be added to the subscripts.  —DIV (128.250.80.15 (talk) 00:50, 28 July 2008 (UTC)
replies: text: I take your point, but IUPAC specifies the use of a capital S (not even  S or s). See also the discussion above where I am suggesting a change in the Greek alphabet used here. I'd say that adding explicit notation that the quantity is per mole or per unit mass is unneeded anyway, since compressibilities are necessarily themselves intensive and so it's always clear in context. Note: you said "intrinsic/extrinsic", but in my line we say "intensive/extensive" to distinguish, say the volume and the molar volume. This is also the Wikipedia way; see intrinsic and extrinsic properties and intensive and extensive properties. KeeYou Flib (talk) 19:38, 21 February 2021 (UTC)
thread_title:  Subscripts of derivatives 

message: The Thermodynamics section of the article contains an extended riff on Z (the compressibility factor) and its behavior in one context (aerospace). It begins with A related situation occurs in hypersonic aerodynamics.. and ends with Ions or free radicals transported to the object surface by diffusion may release this extra (nonthermal) energy if the surface catalyzes the slower recombination process. This all seems out of place in an article which is not focused on Z. Specifically, there is a full article on the compressibility factor and I'd say that it would go there, if anywhere, and not here. I'm not an expert in that area and would not want to move it to compressibility factor myself, but I would like to go ahead and remove it from this article entirely. Thoughts? KeeYou Flib (talk) 16:22, 22 February 2021 (UTC)
replies: text: Yes please! Though if possible, let's not lose anything valuable (so try to roughly make sure that anything notable mentioned here is also mentioned on the other article).--Nanite (talk) 19:54, 22 February 2021 (UTC)
replies: text: Yes, I'm concerned about losing anything valuable as well but again, since I'm not expert in aerodynamics I am hesitant to add it to the compressibility factor page myself. Also, it won't really be lost - all changes are archived - so it can be moved over by a more suitable editor later if we decide to remove it here. KeeYou Flib (talk) 20:16, 22 February 2021 (UTC)
replies: text: In the end I decided to move this material, with some minor edits, to the Aerodynamics section. I don't think it fits in the compressibility factor page very well. I still wonder if it's a bit off the main point of the article, but this change improves the flow of the page considerably, at least it seems so to me. KeeYou Flib (talk) 17:09, 23 February 2021 (UTC)
thread_title:  Propose to delete the extended discussion on Z and hypersonic aerodynamics 

message: Explain in single line Coefficient of compressibility 157.48.155.46 (talk) 00:10, 2 March 2022 (UTC)
thread_title:  Explain in single line Coefficient of compressibility