\documentclass[a4paper]{article}
\usepackage{lmodern}
\usepackage{amssymb,amsmath}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\begin{document}
\thispagestyle{empty}
\noindent
50% is one half.
\\\\
50\% is one half.
\\\\
50\,\% is one half.
\end{document}
