Talk:Physical change

message: Apparently, some people have decided it be fun to edit this page. I recommend that either semi edit protection or full vandalism protection be enacted to prevent future vandalism.
75.181.53.227 (talk) 23:05, 16 December 2008 (UTC)
replies: text: Rule of thumb: The more likely a page will be read by junior high students, the more likely it is to be modified inappropriately. I favour semi-edit protection. So, how do we set it up? Ronstew (talk) 04:08, 17 December 2008 (UTC)
replies: text: ? 50.238.66.122 (talk) 12:19, 9 September 2022 (UTC)

text: no 50.238.66.122 (talk) 12:19, 9 September 2022 (UTC)
thread_title: Recommend Edit Protection

message: When NaCl dissolves in water, it dissociates into Na+ and Cl- ions. Do we consider this a chemical reaction? Simple evaporation of the water restores the salt crystals. Ronstew 03:50, 22 February 2007 (UTC)
thread_title:  Ions in solution? 

message: User 72.140.220.86 put this in the body of the article:
:THESE ARE NOT PHYSICAL CHANGES! Crumpling a paper doesn't change the paper. Similarly, smashing a piece of ice is not a physical change. MELTING THAT ICE IS A PHYSICAL CHANGE. Physical changes involve a change in the intermolecular forces between molecules. Chemical changes are changes between the intramolecular forces resulting in a new bonding conformation.
:Maybe one of us needs to add some references, no?
It would be nice if the user had offered a reference of his own, but we should consider the comments. I note that in the user's terms, smashing ice IS a physical change. Intermolecular bonds are broken, which seems to me to be a new conformation.
User 72.140.220.86, can you give an example of a physical change that is not a state change? I wonder (and am not being sarcastic) if the creation of an artificial diamond from graphite might qualify under your definition. Ronstew (talk) 06:12, 9 February 2009 (UTC)
replies: text: Smashing a piece of ice and melting them would both be physical changes, it isn't changing what it's made up of. Glacialfox (talk) 23:12, 15 December 2011 (UTC)
thread_title:  Dispute over some examples 

message: the way a chemical reacts is also the way a dog barks.
166.62.152.231 (talk) 23:28, 22 March 2015 (UTC)
replies: text: as you have not requested a change. Please mention the specific changes in a "change X to Y" format. --I am k6ka Talk to me! See what I have done 23:37, 22 March 2015 (UTC)
thread_title:  Semi-protected edit request on 22 March 2015 

message: Could one please add, that some alloys e.g. high tin bronze form intermetallic phases which are regarded by many chemists as new compounds, but not as mixtures? They behave in the same way as silver oxide, which is a chemical compound, but not a mixture of oxygen and silver, although one can simple heat silver oxide to seperate it into oxygen and silver. The structures of those intermetallics are very different from the lattices of the pure elements and inded they are in many aspects more like ceramics than metals.
This shows us, that the difference between chemical and physical changes can be blurred in "real" settings although the concept is very useful for idealised and simplyfied model settings.  — Preceding unsigned comment added by Xyrofl (talk • contribs) 13:35, 30 April 2015 (UTC)
thread_title: Alloys