Talk:Chemistry

This article was the subject of a Wiki Education Foundation-supported course assignment, between 28 January 2019 and 13 May 2019. Further details are available on the course page. Student editor(s): Kevyeung55 (article contribs).

Request to remove confusing language from Redox subsection 9-27-2019

The statement is made in discussing a change in oxidation state that "Oxidation and reduction properly refer to a change in oxidation number—the actual transfer of electrons may never occur. Thus, oxidation is better defined as an increase in oxidation number, and reduction as a decrease in oxidation number. " I take issue with the bolded text, as it is at best extremely confusing, and I would say that it is wrong.

While oxidation state is a formalism, it is a formalism used to describe the distribution of electrons in a molecule. Even in the case of an intramolecular redox event where an oxidation state of an atom changes but the system does not gain or lose electrons, the change in that number is very much intended to communicate some movement/transfer/reorganization of electrons. To suggest that such a change in number could not connote this completely undercuts the concept and the rationale for continuing to include in standard chemical education.

Request: please delete the bolded clause. — Preceding unsigned comment added by 128.103.90.19 (talk) 22:01, 27 September 2019 (UTC)

Etymology section

Contains tortuously long sentence which would be more easy to understand if broken into parts. The sentence would be better with the author quoted first, followed by the definition. Timmytimtimmy (talk) 15:09, 7 June 2020 (UTC)

Similar issue in poorly constructed second sentence of “Matter” definition. Timmytimtimmy (talk) 15:15, 7 June 2020 (UTC)

Difference between chemical compound and molecule

I am quite ignorant in chemistry but I wonder why molecules and chemical compounds are considered as two different things, the chemical compounds from reading the article can be understood that it is as if they were simpler but in the end they are not molecules anyway?

--Unvers (talk) 14:46, 2 August 2020 (UTC)

Scientists like to classify things, so having very specific meanings of terms helps with that. Here are two main ways of seeing the differences between chemical compounds and molecules. First is the scale: a compound is a collection of molecules. There might properties related to it being a bulk amount, for example, how the discrete molecules interact with each other, not just each on its own. Second is the chemical elemental composition: a molecule can be composed of any number of different elements but in order to be a compound, its molecules must contain at least two different elements. One effect of "all same vs several different" relates to symmetry of the bonds and atomic locations, which leads to all sorts of other structural and property differences. By contrast, an allotrope is a molecule containing all the same element. DMacks (talk) 15:26, 2 August 2020 (UTC)

This won't help ;-) but WP:ELEMENTS people have introduced to me: an element per concept is not the substance (think neon Ne, is not Ne₂). -DePiep (talk) 00:41, 3 August 2020 (UTC)

Atoms, molecules, elements and compounds are all different terms and are definitely different. Atoms and molecules are microscopic entities while as elements and compounds are used to denote bulk pure matter.

An element is a bulk matter made up of single kind of atom while a compound is a bulk matter formed by definite ratio combination of two or more type of atoms.

Atom, on the other hand, is a microscopic particle which is smallest unit of an element showing it's properties and not capable of free existence ( in general) . Molecules are smallest particles of an element or compound that can exist freely and that shows all properties of that element or compound.

Semi-protected edit request on 21 October 2020

2409:4072:E85:9498:5088:30DC:7721:71E9 (talk) 05:54, 21 October 2020 (UTC)
Lose more money

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. -ink&fables «talk» 05:59, 21 October 2020 (UTC)

Four types of chemical bonds?

Why does the summary say there are four types of chemical bonds? Where are metallic and dipole-dipole bonds? AstroRP (talk) 14:51, 6 November 2020 (UTC)