# Tag Info

### Poll: mhchem syntax for electron configuration

In order to get $\mathrm{[Kr]\mskip2mu4d^{10}\mskip2mu5s^1\mskip2mu5p^3\mskip2mu5d^4}$, I'd prefer to input $\ce{[Kr] 4d10 5s1 5p3 5d4}$.
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### Mhchem feature request: strikethrough and crossout reaction arrows

Thanks for your nice words about mhchem. I am happy to implement this feature. In fact, it already is listed on my to-do list. There are four steps, that I need to decide on, for each mhchem feature ...
• 3,296
Accepted

### Green checkmark or red X with Mathjax/mhchem?

CAVEAT: Due to the use of Unicode, the below may not render properly on all systems, especially mobile devices. (Thanks, Martin!) Green boxed checkmark ...
• 16.9k

### Green checkmark or red X with Mathjax/mhchem?

You can use the following for a green check mark since it is implemented in amssymb: $\Large\color{\green}{\checkmark}$ ...
• 42.7k
Accepted

### What is the standard way to denote physical states in a chemical reaction?

States of aggregation should not be subscripted, it is not wrong, but the recommendations (Sec. 2.1.) are different. The document recommends that: The symbols should be printed in roman type ...
• 42.7k

### FAQ: How can I format math/chemistry expressions on Chemistry Stack Exchange?

(4) Learning by example The MathJax and mhchem syntax in the left-hand side must be enclosed in single dollar signs $...$ for an inline (smaller) equation, or ...
Accepted

### Unknown Notations

It really is tricky to judge what is official and what is not. Here is my take on the several issues. This is not something that should be implemented in mhchem, as I think it is just sloppy ...
• 42.7k

### What happened to writing ions with \ce?

This change was introduced with MathJax/mhchem v3. That's because it is the recommended way of writing. It is IUPAC's recommendation. Red Book section IR-4.3 shows examples, but is missing a clear ...
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### Poll: mhchem syntax for electron configuration

In order to get $\mathrm{[Kr]\mskip2mu4d^{10}\mskip2mu5s^1\mskip2mu5p^3\mskip2mu5d^4}$, I'd prefer to input $\ce{[Kr] 4d^10 5s^1 5p^3 5d^4}$.
• 3,296

### Green checkmark or red X with Mathjax/mhchem?

A meta answer to a meta question, making it meta². Be careful with conventions like this. They are not as intuitive and universal as you might think. I've seen ✘ Artificial Flavours written on ...
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### How to solve mhchem/MathJax rendering problems

So, after failing to reproduce the problem in another browser, I have discovered my own answer. I want to leave this here for other folks who encounter this issue. The problem is in how you tell ...
• 41.8k
Accepted

### Extra spacing before mhchem super/subscripts

This doesn't look right. $\mathrm{|{}^1H|}$ $\mathrm{|{}^1H|}$ and $\mathrm{|\ce{^1H}|}$ $\mathrm{|\ce{^1H}|}$ should give the ...
• 3,296

### Chemical formulas with fractional numbers are displayed wrongly

As a workaround, you could use $\ce{$0.5$\,H2O}$ to get $\ce{$0.5$\,H2O}$

### Is HTML banished?

As the main offender, let me try to give an explanation. For the sake of full disclosure, this is the - admittedly canned - comment, that was supposed to be in the edit summary: I have ...
• 42.7k

### Chemical formulas with fractional numbers are displayed wrongly

Or you can use $\ce{1/2\,H2O}$ to get $\ce{1/2\,H2O}$.
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### Formulae with charge and number of atoms (e.g. sulfate ion) aren't displayed properly

The documentation you linked is for mhchem v 4.01 (dated 23 April 2015). It is likely that Chemistry.SE uses an older version of the package that renders charge differently. Also note that Chemistry....
• 41.8k
Accepted

### Mhchem broken on mobile

This bug was caused by /sites route in the stackexchange api not returning MHChemMathJax in markdown_extensions due to ...
• 101
Accepted

### Why two different print styles for the x's?

You are mixing chemistry typeset with maths typeset; I don't think that the mhchem module is set up for this. There is probably much more wrong than what you consider a bug. Assuming $K$ is an ...
• 42.7k
Accepted

### Why is rendering of this pu markup weird?

It's because you have a tiny, invisible character between the 8 and the 0. Move your arrow keys back and forth inside the text; you'll find you need one extra key to traverse the gap between 8 and 0. ...
• 66.9k

### What happened to writing ions with \ce?

This was a change that was recently introduced to mhchem. (‘recently’ meaning ‘in the latest version’.) The change was made because IUPAC explicitly says the charge ...
• 64.8k

### Chemical formulas with fractional numbers are displayed wrongly

This issue has been solved since mid of 2016. $\ce{0.5H2O}$ renders as $\ce{0.5H2O}$. Short background: MathJax is NOT LaTeX. MathJax is a complete re-...
• 3,296

### Plus-minus sign messes with mhchem's \pu command

Thanks! Some of the things are already fixed on my harddrive (the "undefined" error), but not published yet. The others, I take as valid input for my todo list. For now, ...
• 3,296
Accepted

### What to do if mathrm is hugging physical units?

TL;DR: What is the need of it if mathrm is doing the job properly? – Apoorv Potnis There is no need. There always was a demand for the ...
• 42.7k

### Polymer formula bond-bracket crossing representation

mhchem doesn't support this yet. I'll put it on my the (mid-term) to do list. Thanks for the link to the IUPAC document. Please, please, don't write spacing commands inside ...
• 3,296
Accepted

### MathJax mhchem editor

Yes, see Introducing: Markdown Shortcuts for StackExchange. Of course, this doesn't change the fact that you will need to learn a new bunch of shortcuts (or customise them). That is all we really have,...
• 66.9k
Accepted

### Plus-minus sign messes with mhchem's \pu command

MathJax/mhchem 3.0.6 should fix the issues. It supports all standard uncertaincy notations as listed at https://chemistry.stackexchange.com/a/58667/24052. It will take a week or so to make its way to ...
• 3,296