Questions tagged [notation]

A system of written symbols used to represent qualities or quantities, elements or molecules, or formulas in general. Usually a notation follows a convention or a guideline, often published by IUPAC-IUPAP. This tag should be used for questions regarding the proper use of a notation or misleading or uncommon notation in the scientific literature. Do not confuse this tag with the [nomenclature] or [terminology] tags.

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Oxide content description

From time to time, I come by to see what people do with my mhchem package. Here, I came across a notation that I did not know yet: $\ce{K2O-nSiO2-xH2O}$ and $\ce{K2O - 3.2SiO2 - 2.7H2O}$ What is this?...
6
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0answers
94 views

Is it correct to use the symbols (l) and (g) in every reaction?

I know that this question might sound stupid to most of the people, but for a chemist noob like me is not very clear. So, here's the main question: Is it appropriate to use the symbols (l) for ...
5
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0answers
67 views

Is there a particular name for a Hill formula or sum formula omitting hydrogen?

Often, single-crystal X-ray diffraction analysis determines the non-H atoms first, and eventually puts hydrogen atoms "as riding" on idealized positions in respect to heavier atoms (e.g., C, O, N), ...
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511 views

Platt's Notation/Nomenclature for transitions

How do you read Platt's Notation / Nomenclature? Where can I learn this? Some examples where I've seen this mentioned: In Platt's notation the transitions are designated as $\ce{A -> B}$ and $\ce{...
5
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118 views

What are the essential arrows for entering chemical equations in text?

I'm the author of a custom chemistry keyboard on iOS. I am looking at improving the selection of Unicode arrows I can provide. When the device is a phone in portrait mode, I don't have a lot of extra ...
5
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0answers
155 views

Side chain formation in polymerisation of ethylene

I am having difficulty understanding (or at least need confirmation of my understanding) of this diagram regarding the formation of sidechains of polyethylene. If someone could explain it, that would ...
5
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0answers
121 views

Raoult's law: is the molar fraction the molar fraction in the entire system?

I have two physical chemistry textbooks, one by Atkins and one by Levine, which seem to differ in their notation used when describing Raoult's law. Atkins talks about the molar fraction term in ...
4
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0answers
44 views

Multiplicity letter codes for large amount of states

Well, let's say we have a large amount of states computed (e.g. over 50), all with the same multiplicity. So, our ground state can be $X^2\Sigma^+_g$ and we can continue with $B^2, C^2$ etc. as ...
4
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0answers
1k views

State symbol for electron

Is it correct to write a state symbol of "g" or "l" for an electron? In the textbook I am currently reading, the state symbol "g" was used for the electron when it described the electron gain by a ...
3
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0answers
58 views

Is there a standardized way to assign a label to the symbol of a chemical element (in a published work)?

When referring to a particular atom, both in text and when using a graphical representation, several conventions are being applied. In the field of crystallography an arabic numeral either follows ...
3
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0answers
68 views

Formating chemical equations for proteins binding in multiple configurations

I am working on problems involving protein-protein binding, particularly ones in which two proteins may bind in two or more configurations, and where some of the resultant structures may also bind ...
3
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0answers
327 views

Various meanings of Ka, Kb etc

A little while back, I introduced the feature to mhchem to properly format $K$ constant variables, like $\ce{Ka}$ rendering as $K_\mathrm{a}$, ...
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0answers
73 views

Why is U the symbol for lattice energy?

I often see $U$ or even $\Delta U$ being the symbol for lattice energy. Why is that? Does it refer to internal energy?
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37 views

Drawing bonds and delocalised electrons in condensed formulae

The $\LaTeX$ mhchem package provides commands for drawing bonds within condensed chemical formulae. Some of them have a clear allocation to covalent bonds while others have not. Single, double, and ...
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41 views

What is the difference between these notations and terms?

I can't tell if they're being used interchangeably or if there's some nuanced difference betweem them. Here they are: $E^∘$ $E_0$ $E_h$ $E^⦵$ If I understand correctly, electrode potential is the same ...
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54 views

Are Alloy Compositions Given in Weight Percent or Atom Percent

Often times I see alloys described like this, Lockalloy is an alloy that consists of 62% beryllium and 38% aluminum Are the precentages mentioned here in weight percent or atom percent? Is there a ...
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56 views

What do γ (gamma) and λ (lambda) mean in organic chemistry?

From the Wikipedia entry on Cyhalothrin: Pyrethroids such as cyhalothrin are often preferred as an active ingredient in agricultural insecticides because they are more cost-effective and longer acting ...
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43 views

Writing water as a reactant in acid/base dissociation (Brønsted Lowry)?

The dissociation of $\ce{HCl}$ in water is written as: $$\ce{HCl (aq) -> H+ (aq) + Cl- (aq)} \tag{1}$$ Sometimes we also include $\ce{H2O}$ as a reactant to stress the fact that the protons are not ...
0
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0answers
158 views

What is the correct electron dot notation of carbon?

My book says that the dot notation for Lewis structure of carbon has 2 possible ways: two dots on the right, one on the top, one on the left one dot on all four sides Why are both of these correct? ...
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29 views

Curved Bonds in coordination compunds

This question is regarding a notation I saw in my textbook. Cobalt ethylenediamine complex was represented like this in the book But this structure which I found on the internet gives a clear picture ...
-2
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0answers
30 views

Need help with chemical notations

I am currently investigating chemical properties of elements from Wikipedia. I am not a chemist and have some troubles understating your notation. There is a property called "ionic radius" ...