EDIT: It is already fixed in the newer atom releases.
atom on a terminal will show you why:
/usr/share/atom/atom: error while loading shared libraries: libXss.so.1: cannot open shared object file: No such file or directory
This solution for this error is simple. Just run the following command on a terminal:
dnf install libXScrnSaver
Seems that the RPM is missing this dependency. The bug is already reported here.