4

As pictures tell the issue better than I could I'm just gonna insert a screenshot of the problem right off the bat. Image of the Problem

My problem is concerning the undesired whitespace between the second column of five elements and the five pluses before the five n's. LaTeX code of same looks like this:

\documentclass[12pt]{article}

% Maths & Chemistry Preamble %
\usepackage{amssymb, amsmath}
\usepackage{mhchem}

\begin{document}

\begin{equation}
\ce{^{235}_{92}U + ^{1}_{0}n -> ^{236}_{92}U^{*} ->[\text{85\% nuclear fission}]} 
    \begin{cases}
        \begin{align*}
            \ce{^{144}_{56}Ba &+ ^{89}_{36}Kr &+ 3^{1}_{0}n} \\
            \ce{^{144}_{55}Cs &+ ^{90}_{37}Rb &+ 2^{1}_{0}n} \\
            \ce{^{140}_{54}Xe &+ ^{94}_{38}Sr &+ 2^{1}_{0}n} \\
            \ce{^{146}_{57}La &+ ^{87}_{35}Br &+ 3^{1}_{0}n} \\
            \ce{^{160}_{62}Sm &+ ^{72}_{30}Zn &+ 4^{1}_{0}n}
        \end{align*}
    \end{cases}
\label{eq:u_1}
\end{equation}

Packages used are amsmath, amssymb and mhchem. All I want to achieve is to have the pluses in line while minimizing the space to the left of them.

Thank you in advance, whiterock

0

1 Answer 1

5

Just use an array here. You may want to add one more @{} or some other spacer onto the left of the first column.

% arara: pdflatex

\documentclass[12pt]{article}
\usepackage[version=4]{mhchem}
\usepackage{siunitx}

\begin{document}
\setcounter{equation}{4}    
\begin{equation}
    \ce{^235_92U + ^1_0n -> ^236_92U^* ->[{\SI{85}{\percent} nuclear fission}]} 
    \left\{\renewcommand{\arraystretch}{1.2}\begin{array}{l@{} l@{} l@{}}
        \ce{^144_56Ba &+ ^89_36Kr &+ 3^1_0n} \\
        \ce{^144_55Cs &+ ^90_37Rb &+ 2^1_0n} \\
        \ce{^140_54Xe &+ ^94_38Sr &+ 2^1_0n} \\
        \ce{^146_57La &+ ^87_35Br &+ 3^1_0n} \\
        \ce{^160_62Sm &+ ^72_30Zn &+ 4^1_0n}
    \end{array}\right.
    \label{eq:u_1}
\end{equation}  
\end{document}

enter image description here

5
  • 2
    Thanks a lot, brilliant answer and kind of an instant one too. I just wish these simple alignment jobs I am always struggling to pull of wouldn't require so much effort to complete.
    – whiterock
    Commented Jan 28, 2016 at 16:24
  • 2
    By the way, you could save some typing with ^235_92Uinstead of ^{235}_{92}Uand ->[{...}]instead of ->[\text{...}], but that's down to personal preference.
    – mhchem
    Commented Jan 28, 2016 at 21:00
  • 1
    @whiterock you're welcome. Yes, sometimes this is a bit of work, but actually, I was surprised how simple it was regarding the alignment operator inside the \ce-command. @mhchem, to be honest, I did not take a look on the chem part, I introduced your short style to my answer. Thank you.
    – LaRiFaRi
    Commented Jan 29, 2016 at 9:46
  • @mhchem Thank you, did not know that - fantastic to get a response directly from the creators.
    – whiterock
    Commented Jan 29, 2016 at 9:51
  • @whiterock - The U 235 fission product isotopes presented in the answer to the OP differ from the product isotopes presented at another (presumably reputable UC Davis) website: 21.6: Nuclear Fission at chem.libretexts.org/Bookshelves/General_Chemistry/…. Are the differing isotopic values, eg Ba 144 (in the OP) vs Ba 141 (from the website), significant, or do the differences merely represent the plethora of Ba isotopes that can result from the fission of U 235? Thank you! Commented Aug 31, 2022 at 19:20

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .