# Chemformula: The negative charges are barely visible

While writing a chemistry document I've noticed that the negative charges in chemformula are barely visible. I've included my whole preambule just in case there's a problem between packages:

\documentclass[14pt]{extarticle}
\usepackage[utf8]{inputenc}
\usepackage[margin=0.3in]{geometry}
\usepackage{polski}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amsfonts}
\usepackage{wrapfig}
\usepackage{caption}
\usepackage{hyperref}
\usepackage{siunitx}
\usepackage{chemfig}
\usepackage{indentfirst}
\usepackage{chemformula}
\usepackage{amssymb}
\usepackage[T1]{fontenc}
\usetikzlibrary{positioning}
\newcommand{\nparagraph}[1]{\subparagraph{#1}\mbox{}\\

}
\setchemfig{[]atom sep=3em,bond style={line width=0.06642em}, bond off set=0.1 em, double bond sep=0.35700 em, ]}
\renewcommand\qedsymbol{$\blacksquare$}
\begin{document}
Examples:

\ch{OH-} \par
\ch{H+} \par
\ch{Mg2+} \par
\ch{Br-} \par
\ch{Ch3COO-}
\end{document}


The output is as following:

Is there a way to make the charges, especially negative, bolder and more visible?

\documentclass[10pt]{article}
\usepackage{chemformula}
\setchemformula{charge-style=math}
\begin{document}
Examples:

\ch{OH-} \par
\ch{H+} \par
\ch{Mg2+} \par
\ch{Br^{-}} \par
\ch{Ch3COO-}
\end{document}


• Excellent...I have seen also the same question and I was working on. – Sebastiano Apr 20 at 21:04
• For circles around the charges you can try \setchemformula{circled=all} and for their specification \setchemformula{circletype=chem|math} – Excelsior Apr 20 at 21:14